ON THE SECIMENTAL EXCRETORY ORUANS O F CRUSTAOEA.
439
Notes on the Segmental Excretory Organs of Crust;icoa.-I-IT.
By
H. GRAHAM
CANNON, M.A., D.Sc., F.R.S.E., P.L.S., Professor of
Zoology, Sheffield University, :itid Miss 8. M. MANTON, B.A., Yarrow
Student oE Girton (jollege, Cambridge. (Prom the Zoological Department of the Imperial College of Science and Tecl~iiology,South Rensington.)
(Text-figures 1-7.) *
[Read 20th January, 1927.1
CONTENTS.
I. The Pattern of the Maxillary Glands in the Rranchiopoda and in
Anaspides.
11. On the Sphincter Valves of the Naxillnry Glands of ChirocephaAcsand
Anaapides.
111. On the Segmental Excretory Orgms of the Mysid Lophogaster typicus.
1V. On the Antenna1 Glands of some Euphausiacen and of the PenEeid
Prawn Gennadaa elegans.
I. THE PATTERN
OF THE MAXILLARY
GLANDSIN THE BRANCHIOPODA
AND IN ANASPIDEE.
The coils of the efferent duct of the maxillary gland of tlie Branchiopod% exhibit a very constant pattern and call all be traced from the
nrrailgement seen in Estheria. Tn this form the duct leaves the elid sac
ai,tero-ventrally, and curving underneath the attacliuient OE the adductor
lnuscle to the carapace passes upwards and forwards over the top of the entl
sac to a point marked X in text-fig. 1. This point is situated in the iiiipte
formed by the attachment of the dorsal lorigitudinal muscles arid the levator
muscles of the mandibles. This loop of the duct is marlted 1 in text-fig. 1.
The duct then turns b:iclr on itself, passes backwards, clon.iiwards, aud then
forwards, thus forming n second loop marked 2. It has now r ~ c l i e l ltho
point Y just below the end sac. I t again reverses its direction and ruiining
p:lrallel to the loop 2 reaches a point Z immediately below X, where it loops
routid the jiinction between the end sac and the remains of tlie first dorsal
c~loiriicsac (Cannon, 1924, p. 403), and then p:tsbes ventrally to ils opening
011 the maxilla.
Thct loop between Y and Z has been marked 3, and the
portion of the duct between Z and its exit has been marlted 4.
This pattern, the devolopincnt of which has h e n dealt wit11 in detail by
Callnon (1924), is the same as t'iat shown, according to Nowikoff, in the
nearly allied genus Linznadia,and can be taken as typical of the o r d c ~Conchostraca. The other orders of the Branchiopoda. can tm placed in two
* The cost of the text-figures 118s been met from the Westwood Fund.
LINN. J0URX.- ZOOLOUY, POL. XXXVI.
36
440
PROF. H. GRAHAM (IANNON AND MIS8 S. M. MANTON ON
TEXT-FIG.1.
Reconstructiona of the mnxillrtry glands of various Brmchiopodn.
Thnt of Sida is after Claus.
THE BEQMENTAL EXCRETORY ORGANS O F ORUSTAOEA.
441
groups-the Notostraca and Chdocera, on the one hand, in which the pattern
of tlie maxillary gland duct is closely similar to that of the Uonchostraca, aiid
tlte Anostraca in which there are important differences.
Thr anatomy of the tnaxillslry gland of Apus has been described by Claus,
and, allowing for certnin obvious inaccuracies, it is eesuntially the same as in
Estheria : firstly, he states (1893) that the loop 1 joins the loop 4 before tho
latter opens to the exterior. This would mean that there wore two channel9
leading from the end sac to tho exterior, one long and coiled ilia tho loops 1,
2, 3, and 4, and the other short and direct via the loop 4 alone. From the
fact that otherwise tlic gland SO closely resemLles that of Estheria, we tliinlr
it most probable that Claus is ingorrect. The socond point on which we
disagree with Clam’s account is that he states that loop 3 encircles the
“ schalentnusltel.”
By this, presumably, he means an adductor muscle. We
can find no trace of such a muscle, and Zacldacli (1841) in hi$ account of the
musculature does not mention it. By comparing our own prepnrations of
Lepiduruz * with Clnus’s figures of Apus, it is clear that there is no essential
difference between tlie glands of tlic two foriiis, a i d iri Lepidurus there is
cerhiuly only one channc.1 leading from the end sac t o the exterior, :tiid there
is no adductor muscle (text-fig. 1). Apparently what &us inistook for tllo
attachment of an adductor muscle was the fenestrated portion of the elid silo.
Tile end sac of Lqidtwus has a pecii1i;ir shape. I t is produced into three
lobes. Two of these are short and project into the cavity of the trunk, while
the third is a n elongated arid fenclstratod lobe projecting irito the slrell-fol(]
between loop 1 ventrally and loop 3 dorsally. I t occupies thc area C1:lua
inistook for the attachment of the adductor muscle. I n the young speciiiielis
thitt we sectioned we have not been able to find any trace of a sphincter 1 alve.
The forin of the maxillary gland both of Lepidurus and d p u s cun be considered as that which would be obtained if the adductor iiiuscle of Eststheyia
were removed and tlie space SO leEt obliterated by the coils of the gland being
pressed together, and then the whole structure stretched out in nn antaroposterior direction. The maxillary gland of the Conchostracan Limiietis
sllows an interesting intertnediate stage between JIJstIie?*iaand Lepidilc7.lrs
(text-fig. 1 ). Postoriorly its coils ant1 end sac are crowtlecl cJosely tog&.r
:rnd are coinpactly elongated, as in the Notostraca, while :interiorly tile
&jllctor llluscle is present and it has the typical form of lCsthe?*ia.
Alllotjg the Cladocera it is remarkable that it is in the Gjmnomernll
polyp/ieinus that a pattern most similar to that of Estlieria is found (textfig. 1). In this form, with the shifting of the surface of nttachinent of ttie
adductor inuscle froui the outer ectoderm of the shell-folll on to the i n i l t ! l
surface of the coils, that p:wt of loop 1, which in Estlieria passes fbrwar,ls
unJerneat11 the adrluctor muscle to enter the end sac anteriorly, has slioittn, ,I
* We have to thnlilr Prof. D. M. Fedotov, of tlie University of Leuingrad, for
supplying us with specimens of &?pidurue, Limneth, nnd Eafhwin.
36*
Itiiit~ly
442
PROF. H. QRAHAM OANNON AND MIES 8. M. MANTON ON
so that it now enters the end sac posteriorly. Otherwise the gland shows
the typicill Estheriid form. Tlre maxillary gland of the aberrant Gymnomerat1
Leptodora waP figured by Weisitiann (1874), but the arrangeinent of the
coils is not at all clear. Calman’s statement that the gland does iiot lie in
the thickness of thc shell-fold is not strictly correct. The end sac and a
sinall coil lie latorally in the posteriorly placed caraptice, and froin thiH n
large duct, probiddy representing loops 8 and 4, runs forward to the opening
on the body-w:ill (text-fig. 1). The pattern of tlie coils is very siniple, iind
it is not possible to make any coinparison of value with that of Estlieria.
The ducts of the Calyptomeran Cladocera have been described by Claus
(1875), but unfortunately the orientation. of his figures is not stated and so it
is so~netimesdifficult to interpret them. The main characteristic throughout
the suborder is that the loops 2 and 3 have straightened out,, so that the
point Y has come to lie posteriorly or ventrally. This is best seen in the
less specialised Ctenopoda-e. g., Sitla crystallha (text-fig. 1). In the Anomopodn the loop 2 develops an S-shaped twist, 0. g., in Simocephalus, and in
a inore pronounced degree in Daphnia pulex and twgna, this bringing the
point Y more ventriil. The relation of the adductor muscle to the coils is
not illustrated by Claus. However, i n S. wetulus, in which the muscle is
double, a minute strtind apparently corresponding to the adductor muscle of
the Coiichostraca ends against the outer fold of the shell just above loop 1,
but the main part of the muscle ends against the ectaderin where this reflects
to form the shell-fold, and so does not interfere with the looping of tlic duct.
The differences in the pattern of the in:ixillary gland in the Anostracii, as
exemplified by Chirocephnlus, are undoubtedly connected with tho absence
in this suborder oE the ciirapnce and the resulting disappearance of tlio
adductor niuscles. In the other suborders tho coils :ire lodged within the
narrow cavity of the shell-folds, and there is no room for the loops to overlap
to any marked degree. I n Chiroceplialus this restraining influence is absent,
and so the gland pojects into the body-cavity as a more or less round inass
in which the loops overlap (text-fig. 2). This inakes comparison with
E&&u somewhat difficult, but there are two angles in the coils which agree
coinpletely with the corresponding points in the other Branchiopoda, and
tllese give ths clue to the homologies of the various loops of the gliinds.
In Clh*ocephaliis,as in Estlieria,
These wo believe to he the points X and
they occur froin tho e a r l i d iippenrance of the priinordia of the coils, lodged
i n the angles between the anterior attactiineiit of the dorsal longitudinal
lnuscle and the levator muscle of the mandible. From one of them a duct
leads directly to the exterior, and so this must be the point Z. From the
other, X, a loop leads direct to the end sac. This is the loop 1, but, owing
to the absence of the adtluctor muscle, it does not show the characteristic
downwards nnd upwards loop which in .,%theria is necessitated by its passing
underneath the iidhctor muscle attachment. The point Y iu (Ihirocephalus
z.
THE SEGMENTAL IEXURETORY ORaANS Ofi CRUSIAC$A.
443
has passed backwards, so that the loops 2 and 3 have become straightened
out %a in the more primitive Daphnids.
In the Syncarid Malacostracan, Anaspiiles, the pattern of the maxillary
gland shows a very striking and significant similarity to that of Cl~irocephalzrs
(text-fig. 2). As in the latter theru are two angles in the coil that occupy
TEXT-FIG.2.
ESTHERIA TYPE.
Ilecouatructioi~sof the maxillary glands of CJbiroccphalus nud Anuapidea.
the space between the anterior attachment of the dorsal longitudinal muscle
and the levator muscle of the mandible. From one of these a loolb runs
directly to the end sac, w i h , in the iniddle of its length, an S-shaped twist,
niid tliis inust be the loop 1 running froin tliv point X .
The loops 2 and 3
running posteriorly froin the points X a i d Z respectively are straight and
444
PROF. H. QRAHAM CANNON AND MISS f3. M. MANTON ON
are comparatively short, so tlia t the point Y conies to lie anteriorly to the end
sac. Thus, except for the ttiiiior. diffei-ence in tIie S-s1i:iped twist occurring
iu loops I itlld 4, tIierc is n complete agreement between the pattern of the
coils of Anaspitles and Cliiroceyliuluu.
The occurrence of the looping of the coils of the inaxillary glailds of two
such different forms as A naspitler and Cliirocepltulits probably indicates
necessity, but the occurrence of a
nothing more tli:in a siinilar ~~hysiological
similar pn ttern i n that looping w0 consider as inore sigiiificant. w e see 110
reason for a t t r i h t i n g it to tnero chance, and we think rather that it slioulcl
be talren as an indication of a pliyletic relationship.
Prom sections oE sonie specimens of BatlupEla thitt we were fortunate
enough in obtainiiig through the kinduess oE Professor Zsoholtlre, it is clear
that the pattern of! tlia looping or the duct caiinot be compared with that of
Anuspides, The attunuatutl form of tlie body has drawn out tlie duct into a
long loop extending t'roni the tnaxillary segment to the fourth trunlr segment.
The cliief interest in tlie gland lies iii the fact tliil t, presuiiiably as a result of
the minute size of the adult, the duct has become intrncellular.
LITERATURE
LIBT.
CANNON,
11. Ct. 1924. On the Developnient of an Estherid Crustacean. Phil. Trans. 11.
SOC. London, Ser. U, vul. 212, pp. 396-430, with plates 18-24 and 6 texttip ures.
CLAWS,
C. 1803. Zur lienntniss des Llaues nnd der Eotwickluiig YOU Brimchipus atngnalts
und Apua cancrifovtiaiu. Abli. Ges. Wiss. Qiittingen, Ud. 18, pp. 93-140, with
plates 1-8.
CLAWS0. 1878. Die Schalendriiae der Daphnian. Zeitsch. wiss. Zool. Leipzig, Bd. 26,
pp. 165- 173, with plate 9.
WEISMANN,
A. 1874. Ueber Bau niid LebenserscheillunReii von Leptodora hyiilinra.
Zeitsch. wiss. Zool. Leipzig, 13d. 24, pp. 349-418, with plates 33-38.
ZADDACH, 1% G. 1841. I)e Apodis cnncriformis SchaeK anatauia et historia evolutionis.
Diesertatio inaug., vi & 73 pp. nud 4 plates. Bonnse,
11, ON THE SPHINCTER
VALVES
OF THE MAXILLARY
GLANDS
OF
CHIEOCEPZIALUE
AND ANASPIDEB.
In Estheria there is no sharp distinction between the end sac of the
niaxillary gland and its duct. The end sac appears siinply as the enlarged
ititeriisl termination of the duct. The end-sac cells aro flatter than those of
the duct, but there are no marked histological differonoes between them. I n
Linatzadia, according to Nowikoff (1905), the cells of the end sac differ considerably in their histologicnl detail l'roni those of the duct. But neither in
E s t h e k nor in LimizutEia is there any indication of a iiiuscular vulva between
the end sac and the duct.
I n Chiroc.eplialus, however, not only is there a inarlted difference between
the cells of the end sac a11d those of the duct, but in between the two there
occurs a very well-defined muscular sphincter. I n the adult the cells of the
I'HE SEGMENTAL EXCHETORY ORGANS OF CRUSTACLA.
445
olid sac imitietliately surroiiiiding the entrance to the duct exhibit yery clearly
(leeply stiiining fibrils. About taiglit cells in all forin the valve, the fibrils
running transversely to the directioii of the duct. Tlie distinction betweon
the end sac nnd the duct is very niarlred i n early larval forms, long before the
lumen has appeared in the duct. The end-sac cells :ire much more vacuolateil
than those of tlio duct and tlie cytoplasiri does not stain so readily. From a
study of tile developinent it can I e seen that the valve arises from the endsac portion of tlie gland. A muscular sphincter has not been described in the
tnaxillary gland oE aiiy other Brancliiopod.
I n Anaspides, as in Cl&myuliaZus, the end sac is clearly difi'erentiated froin
tho cfferent duct, and a t the junction between tlie two t h c w occiirs a definite
TEXT-FIG.
3.
AN ASPIDES
CHIROCEPHALUS
sections througli the maxillary gland v d v e s of A~citspidesarid Chirocvphnba.
valve. This congists of :I group of three or four cells nronnd the entraiice
into the elid sac wliich project very marlredly into the liinien of tho duct.
The detailed histological constitution of the valve unfortnnately could not bo
made out, as the fixation of the specimen was not sufficiently good (textfig. 3). It resembles, however, very closely the valves of the excretory
glands of ikiphargus and Gamniarus described by Vejdovsky (1901).
Tlie close similarity in the paltern of tlie ninxillary glands of Chirorepha2us
and of Anaspides we tttke as clear avidelice l'or the complete hornologies of
the two glands. That of Chirocephalus has been showra by Cannon (1926) to
446
PROF. H. QRAHAM CANNON AND MISS S. M. MANTON ON
cousist of an entirely mesodermal structure. We'therefore deduce that the
maxillary gland of Ailaspides is siitiilarly of incsodermal origin, and hence
the valve, which in Cliirocepliulur is differentiated actually from the endsaa walls, is also mesoderm:il. The cliief interest in the discovery of a inesodermal valve in Cliiroceplictlus nnd in Anaspidus lies in tho fact that Cannon
has recently demonstrated that the valves of the inaxillary glands of certain
fresh-water Ostracods (1925) and of the antennal gland of the larva of
Chiroceplialus (1926) :ti e of ectoderinal origin. He believes thiit in these
two cases the vnlvcs represent portions of the endaskeletiil systein that Iiavo
second:irily becoinc intc*rcnlated between the end sac and the duct. I n a n
advanced larva of Chiroceplialiis t h e are therefore two segitien tal excretory
organs, the an tennal and the inaxillary glands. Both show the typical
structare of an end sac, a valvc an11 a duct, and i t is reasonable to suppose
that in both cnstls the correspondiug parts function in similar ways ; but
whereas tlie valve of one (the nnteniial gland) is ectoclrrmal, that of the
other (tho maxillary g1;iud) is mesodermal in origin.
Vejdovsky (1901, p. 294) suggested that the valve-apparatus represented
the annelid neplirostomr. H e considered only the coinplex nephrostonie
such as occurs in Lumbricus and into tho coiistitutioii of which mesotlermiil
eleinents enter. I n such a structure the mesodermal portion soparates the
inner mesodurinal structurcs from the outer rctodcrinal portion of the
nepliridium. I n Chiroceplialiis, and presumably in Ana~pitles, the wliole
maxillary gl:ind is inesoderinnl, and thus the valve in separating the end sac
and the duct separates two ~ n e ~ o d ~ r ~structures,
n:tl
so that the valve cannot
be honiologous with this type of nophrostome.
(hiinon Itas already demonstriited (1925) that the ectodernial type of
valve iilso cannot represeiit the annelid nephrostome. I t is an independent
structure ariqing separately from the ectodermal diict, whereas the ectoderinal
iiephrostonie of an annelid alw:tys arises as the iiiner termination of the ectodermal ingrowth to form the nophridium.
The ectoderiiial valvc we have found only i n glands where the duct is of
the intracellular typc and, therefore, according to Cannon, is also an ectodermal structure. I n the antennal gland of Estheria and C/iiroce,vRaZus iiiid
in tlie miixillary and antennal glands of Cypri8 the ducts arc all intracellular,
and in each case there is a valve which there is reason to believe is of ectoderinal origin (1926). I n a Cirripede nauplius we liave found an antenna1
glaiid in all essentials similar to that of a Brancliiopod. It has an intracellular
duct of a few cells only and ii v:tlve altached to the ectoderm as in ChiPoeeplialtis. I n the Copepod n:iuplius, according to Grolhen (1881, 11. 264),
the antennal gland d s o possesses an intracellular duct but apparently no
trace of a sphincter. I n this connection it is interesting to note that tlie
nauplii of the four orders of the unjustifiable group Entomostraca all
possesa antenna1 glands with intracellular ducts, I n the nauplii of certain
THE SEGMENTAL EXCRETORY ORGANS 08 CRUSTAC'EA.
447
Euphausids, the only Malacoatracan nauplii we linvo been able to obtain,
there is, however, 110 trace of antenna1 glatid.
LITERATURE
LIST.
CANNON,€1. Q. 1925. On the Segnientd Excretory O P ~ R I IofS certain Fresh-water
Ostracods. Phil. Trans. R. Soc. London, Ser. U, vol. 214, pp. 1-27, with 2
plates m d 5 text-figures.
CANNON,
H. G. 1926. On the Development of the Friry Slirinip, Chirocephalus draplanur. Journ. Linu. SOC.Land, (Zool.), vol. 36, pp. 401-416, with 2 plates nnd
3 text-figures.
UIZOBBEN,
C. 1881. Die I"~itwiclrlungsgeschiclite der Cetochilrts repteiitvionalis. Arb.
Zool. Iost. Univ. Wien, Bd. 3, pp. 243-283, with 4 plates.
NOWIKOFF,
h1. 1905. Untersuchunpeti iiber den Uau der Liimadin lenticulwis. Zs.
wiss, Zool. Leipzip, Hd. 78, pp. 661-619, with plates 19-23 and 6 text-@urea.
VEJDOVSKY,
F. 1901. Ziir Morphologie der Antentien- utid Schnlendriise der Cru*taceen.
Zs. wise. Zool. Leipzig, Bd. 69, pp. 378-397, with plates 26-27 ~ i i d1 textfigure.
111.
O N THE SEGNENTAL EXCRETORY OHUANS O F THE
MYsIu
LOPHOQANTER
TYPICUG.
Of the Peracaridau Malacostraca, the, Mysidaceii relircsent the order which
is most directly related lo the ancestors of ths division, ;md it is generally
accepted that from some primitive Mysid there arosri, 011 the one hand, the
modern Mysids and the Amphipode, and, on tho cther, the Isopods-the
Cuitiacen and Tiinaidacea being offshoots from this latter stom.
T h e segmental excretory organs OF tlie Amphipoda are the aiitennal glands,
and the saiiie is uvuallystated with regard to the Mysidacea. I n the Isolioda,
C~iimacea,and Tanaidacea, however, it is the inaxillary glands that constitiite
the segmental excretory organs. I n all these orders the anleniial glands
may be present during embryonic stages, but they are completely absent in
the adult.
It would he expected from this that the coininoii stock which gave rise, 011
tlie one hand, to the Amphipods and, on the otlier, to the Isopoda would have
poFsessed both aiiteiinal iind maxillary glands. From a comparative study
oE the an:itoiny of the excretory organs of the group, it conld further be
predictetl that in this primitive form the glaiids woulcl coiivist of a simple
end sac with a multicellulnr duct whicli was probably illore bladder-like
than tubular.
'!he Lophogdstridm are usually considered to be a primitive fanlily of
Mysids. Through the kiudness of Dr. Calman we have been rible to
examine the seg~nantal excretory organs of Loplrognster typicus. The
specimens were taken from deep water many ye:irs ago, and no special
precaution had bnen taken to ensure good fisatioii. The preservation,
however, was remarkably good. W e find, as we expected, that tlie adult
148
I’llOF. 11. GIAIIAM CANNON A N D MISS S .
M. MANTON ON
possesses :intenn:il and tnaxilliiry glands, both wcll duvoloped (tcst-fig 4,a
ilnd b ) . We have IJccn able to reconstruct the glantls froni sections, with
the exception of the end sac of the niaxillary gland, only rutnnants of wliiclt
were preserved. Both glancls are siniilar in structure, and closely resemble
the antennn- gland of l1ettzi)nysis lantornm (text-fig. 4, tE and e ) . The end
sac of the autcnnal gland is simple, and tho ducts of hotli are large and
swollen, Lut not coiled. The antenna1 glands of 1)oth 11e))zitiiysis and Lophopster are ronglily shaped lilce mi inverted Y. The two arms of the Y
pass to the end sac and exit, the latter extendiug niorc ventrally than
the fornier. The tail of the Y lies iip the bide of thc body as :i blind
lobe. I n Lophogaster tliis lobo reache3 tho dorsal side of tho body, curling
round the briiin. Iu .Ueen&rysis it is much shorter, the s p c e occupied by
this lobe in 7,oplzogaster being filled by the niore anteriorly situated
stomach. In both, the end sac lies in a posterior bulge at the tme of the
antenna, and do not conirnuiiicate by a conspicuous 1)ore with the duct.
In Heminaysis tho wall of the duct becomes thin where it is pressed ilgaitlst
the cnd silt, and here a group of duct-colls extend sliglitly into the lnnien
of the duct. Through these cells can be seen some ill-defined lacIlil;E,
which may put the end sac in commnniciition with the duct. I n Lopliognster the ond sac is dr:Lwn out :igrinst tho duct, just as in lleniintysis,
and in one specimen a group of duct-cells in size and shape resembling those
nicntioned above seeins to be present. The duct in botli opens to tlie
exterior by a short exit-tube of different histologid cllarilctor nt the base
of the antenna below the end-sac bulge. I n Lop7~ogastertho exit-tube opens
on a papilla, the exit-tube occupying tlie whole of this structure. I n the
late embryo of Hemimnysis, just before the young leaves the brood-pouch
the exit-tube also opens on a papilla, exactly as in Lophogaster (text-fig. 4, c).
The antenna a t tliis stage extends ilo\viiwards or backwards. When the
young leaves the brood-pouch, the antenna turns forwards and the posterior
papilla beconies drawn out anti part(ia1ly obliterittcd. The region of the
antenna corresponding to the embryonic papilla now becomes filled with
the enlarged distal part of thc duct. Tho duct of the maxillstry gland of
Lophogaster is quito simple, :inti has no blind lubes. It opens a t the distal
end of the first joint of die tilaxilla, and f’rom the oxit-tube extends a large
dilator niuscle 011 the uppcr posterior sUrfilC0 of the limb.
The segnicnt~lexcretory org:rns of Lophogaster can bu taken as a type
from which the contlitions found in :ill the Peracarida ctn be derived. A
simpla sac-like duet is found i i i tliu nntential g l a d of the Mysid Siriellu
and in various Isopods, such iis Gyge, Plutyarthrus, Porcellio, and Oiiisctis,
some of which inay show one loop. By further elongation and looping of
the duct the sac-like shape will be replaced by the niirrower coiled t j p e
of duct found in the Tauaidacea tind Cumacea, which usually show two
1s
THE SEQYENTAL EXORETORY ORGANS OF CRUSTACEA.
443
loops, aiid in Asellus, Ganzmarus pulex, Niphargus, nnd R Mysid, figured by
Grobben (1881), in which the coils iiro numerons. By partial or coniplete
mppression of one or other of the antennal and maxillary glands tho
conditions found throughout the orders of the Peracarida can be obtained.
TEXT-FIG.4.
HEMIMY515
( a ) External view of n longitudinal reconstriiction of the segmental excretory o r p i s of'
Lophogaster typacus. The possible position of the end sac of the maxillary gland is
indicated by the dotted line.
(6) Transverse reconstruction of the antennal glands of L. typicus, viewed from behind.
c) Longitudinal reconstruction of the antennal gland of a late embryo of Hemimysis
lumorna, just before leaving the brood-pouch.
(cF) External view of a longitudinal reconstruction of the antennal gland of an adult
H. lanaorna.
(e) Transverse view of the antennal glands of H . lanzorns.
ugZ.e., end sac of antennal gland ;
a., antenna ; a.gLiE., duct of Rntennal gland
a.gZ.ex., antenna1 gland exit-tube in its papilla ; CAS., central nervous syetem ;
e., eye ; Z., liver; mdb., mandible ; ma. 1 , maxillule ; mx. 2, maxillR ; 7 n ~ . g ~ duct
.dJ
of maxillary gland ; m.a-.gl.e., end ~ a cof maxillary gland ; ms.gZ.nz., dilntor muscle of
the exit-tube of the maxillary gland ; p., paragnath ; st., stomach ; th. 1, first
thoracio limb ; t i . 2, second thoracic limb.
450
PROF. H . URAHAM CANNON A N D MISS 8. M. MANTON ON
Ui~fortu~iately,it 1t:is iiot boon possible to investigate the segmental
excretory organs of Il’liervzosbuxa.
LITERATURE
LIST.
(~~OBBEN
C.,
1881. Die hiiteuueirdriize der Crustacean.
Ud. 3, pp. 93-110, with plntu 9.
Arb. Zool. lust. Univ. Wieu,
IV. ON TEIIZ ANTENNAL
GLANDSO F SOME EUPHAUSIACEA
AND OF T H E
PENZID
PILAWN
G E ~ N A DEZBGANS.
AS
A surface-view of tlie antenlid gland of Euphausia superbu was figured by
Ziiniiier (1913). He correctly described a ring-shaped duct, but (lid itot
find an elid sac. Chun (1896) also describetl and figured a U-sliaped
tubular nutetiiial gland of :i deep-sea Eujlliausid Styloclieiron, but liis
homologies of tho duct and end S:LC :ire not a t all clear.
We have exaiiiiiied tho antennal glands of iVyctip1ia)ie.s coucliii and of
Styloclwiron ahbrevialuni, and find thoin to be very similar. The aiiteiiiiai
gland of Nyctipliaues forins a compact inass a t the basu oE the witelilia,
and does not extend up the &lea of the body. Tlie end sac is simple and
not lobed, and sliows a one-layered epitlieliuia. Tlie duct is wide and s w like, and opens by t~ short exit-tuhe on a small elevation a t tltc ventral
surface of the limb-base. The duct epitheliutii shows a very coiispicuous
striated border towards the lumen. Tho duct is, however, peculiar in one
respect. It appears in side-view as n hollow ring (text-fig. 5, u and b ) at
the posterior lower end connected with the exit-tube, and joining the end sac
in the middle oE the upper part of the ring. Thus from the end sac
there are two passages to the exit-tube, oiie by the dorsal and posterior
part of the ring and one by tlie anterior and ventral part. The end sac
occupies the central space of the duct. The fixation of‘ the end sac n:is
not so good as that of the duct, aiid no open communication between the
duct and end sac could be found. The intiinate junction between the two is,
however, unmistakable, and is always characterized by a group of cells with
small nuclei bulging irrcigularly into the lutnaii of the ducl (text-fig. 5 , c ) .
There appeared indications in tlie sections of irregular lacunae amoiig tliese
cells.
Tho antenna1 gland of Stylocheiron uhbreviatiilri shows rl siinilar pattern to
that of Nyctiplianes, :ind is not a simple U-shaped structure a 8 Chiin
describes. The valve between the duct and end sac is composed of fewer
cells than in Nycripliaries, but appears to be siniilar i n structure. In one
section (text-fig. 5 , d ) a clear narrow cliannel passes from the end sac to
the duct between tliaso cells.
Thus the antennal glands of Euphausia superba, IVyctiplianeJ coucliii, and
Styloclieiron abbi*eaiutum all show a ring-like duct, and the valves between
the end sac and duct in Nyctipliuws and S/yloclieiron are also similar.
THE SEQIENTAL EXCllETORY ORQANS O F CRUSTAUEA.
451
Zimtner did not cut any sections OE Eupliausia superba, and so we do not
know what the valve was lilro in this form, but it probably resembled
that of the other Euphausids. This type of gland is prohalily typical of the
Euphausiacen generally, and differs froin all other non-labyrinthine anteriiial
gl:~ndsin the s h p e of its duct.
The antenna1 gland of the Penaid prawii Gennadas elegans is of interest in
tbat the adult shows :t duct which has not yet become hbyrintliine ; and
which possesses a well-developed valvu1:tr apparatus between the duct and
end sac-a condition only found, as far as we are aware, in larval Decapocls.
A bladder systeln is also well developed.
TEXT-FIG.G.
Y't
d
Antennnl gland of Nyctiylhanes couchii nnd Stylacheiron nbbt*cuicit~rm.
( n ) Outer view of n longitudinnl reconstruction of the g l a d of N. couchii.
( b ) Transverse section showing n recoiistruction of the glnnd of N. cozrchii.
( c ) Part of n section showing the connection between duct and and SRC of LYcouchii.
( d ) Part of n section showiug the valve between end snc and duct of &!y/ocheim?babbrevintum.
c.n.s., central nervous systom; d., duct of antenna1 gland ; ect., ectoderm ; e.s., end
sac of antenna1 gland nz., inuscle ; st., stcimnch ; 8.) connection between end sac
ond duct.
Tho gliind, apart frorn the bladder system, is lodged in tlie h s e of the
:intenna between the inuscles and the nerve-cord. The ctrd sac shows a
simplo one-layered epithelium, and is thrown into slight folds (text-fig 6,
a and b), h u t is practically :I siini)le sac. Tho duct is sac-Iilre, ~ 1 1 ~wr:ips
1
c:IoseIy round the end sac, leaving it exposed only for a small region 011 tlla
outer side, where the antenna1 gland artery lies close to the end sac. WIiere
the s:tc-like duct touches tho en I SRC it follows the snnie slight lobing of tlie
1:ltter. The duct opens by a short exit-tube on the inner sicle of' tlie linlbLase. The tluct is wide and simph, except a t the upper outer angle aboiBe
rind external to tlie end sac, whore its walls :ire thrown into a f e w folds,
wIiioIi may extend right across the lumen. The end sac opeiiv into the tluct
i n the ~niddleof its outer surface, and this opeoiiig is guarded by a valve.
.
452
PROF. H. GRAHAM UANNON AND MISS 8. M. MANTON ON
This consists of about eight extremely elongated duct-cells round the
entrance, projecting into the duct-lumen. No fibrils of any kind could be
seen in them. I n between the end aac and the duct-wall is a thin layer of
coiinectivs tissue, in which are found numerous t)lood-laouna?- Thesa n re
siipplied with blood froin the a n t e n i d gland artery, which enters the glml
over the exposed part of the end sac, and then spreads out over its surface.
TEXT-FCQ.
6.
Antenna1 gland of Gennndaa elogana.
( a ) IX~grammatictraneverse section showing tbe end suc aud duct and the labra1 connection
between the two ducts.
( b ) Part of R section through the auteund gland showing the comninnication between the
duct a d end BHC and the v d v e .
(c) Dorsal reconstruction of the wbole gland to show the bladder eyetein.
,
gland artery; d., duct of mtennnl
a.L, anterior lobe of bludder systeni ; b . ~ . antennal
gland; e.a., elid SRC of antannal gland ; w., exit-tube of antennal glnnd ; i . ~ . linner
.~
poeterior lobe of bhdder Bystem ; Zbr.c., h b r d commiesurd connection of bladder
system ; m., m u d e ; n.c., nerve-cord ; oea., esophagus ; o,p.l., outer posterior lobu of
bladder systeiu ; p.l.u., union between posterior lobes of bladder system ; at., stomach ;
aub.{rit.Z., sub-intestinal lobe of bladder syatem.
The bladder system is well developed. and can be seen froin text-fig. 6, C.
.\nteriorly the duct givea off II pair of blind sacs reaching to the dorsal part
of the biises of the niitonnules (d).
A transverse commissure through the
THE SEGMENTAL EXCRETORY ORGANS OF URUSTACEA.
453
base of the labrutii below tho nerve-cord joins the duct-systems on each side
(Ibr.c), and two posterior lobes oxtend into tho thorax. These sliift to tbe
sides oE the nerve-cortl and divide into two. The outer lobes piiss laterally
close to the bodj -wall outside the tnusculature, and gradniilly become more
t1ors:il in position till they r c : d i the heart (op.1.). Thuy then unite and aro
closely wrapped round the anterior part of tlie heart, whore they end blindly.
The inner lobes unite (p.Z.u.) above the mandibular tendon and again
separate. A median lobe extends backwards from this union below the
stomach and abovo the liver (swb.zh,Z,). The posterior lobes now lie
below the stomach between tlie liver and the musculature. They bccoine
gradually more dorsal, extending up the sides of the stoilinch until they
lie just below the outer lobes, where they end blindly.
Of tho Peiiceid~c the only nntennnl gland previously tlcscribed is that
of Leucqer (Grobben, 1891). Here also the end sac is sintple and tho
Iiibyrintli abscitt. The duct is ii:trrow and lias two coils, and is thus more
reminiscent of the higlier Per:icaridnn types tltan the I>ecapoda. Tlie
gland is, however, modified by the exlreine 1:iteral coinpression of tlie
animal, the piitteriis of the dncts liaving become :isyninietrical and a union
establislictl betwt.cn the dorm1 loops of tlie ducts on e:icli siilc.
Tho typical atitential gland of a Dec;ipotl consists of an end sac, :i inore or
less complicated duct-system leading to the exterior, divided into n ventral
portion, the lab) rinth, whiclt with the end siic constitutes wlrat is known :is
the “gli~ntlular” part of tho organ, :itid a dorsal portion acting as a
reservoir. The end 5ac is said to be typically many-layered, but tltis is not
so in inany prawns, e. g., Hippolyte, Pandullis, and Genmtlas, or in Cuncer
and Carcinus. The more primitive condition niay be taken t o be that
found in embryos atid inany adults, where the epithelium is singlelayered and the sac not lobod. Such a simple end sac is found in the
adult Hippolyte.
The Decapod labyrinth is formed from ti simple duct by one of two
methods, or a conibination of both. Firstly, tlie duct-wall itself niiry
become folded internally, SO that partitions tire formed dividing up the cavity
of tho duct, and, secondly, the end sac with the closely apposed duct may
hecome lobed, so that the processes froin the end sac push the duct-wall into
folds atid piirtitioiis. No such complica~iousare present in HippoZyte, but
Gennatlas is sect1 to show the initiiil stages of both. I n Ilippolyte vurians
the wholr gland is ronghly sausage-shaped, and lies horizontally s t tlie side of
the bocly. Tlie duct is blnclder-like, tind w r a p almost comldetely round the
end sitc, which lies in the inidclle of tlie glnnd-mass. Anteriorly, the duct is
drawn out into three short processes. Tlie duct in Gennadas near its
openiiig to the end sac shows about two folds projecting froin its all, while
the rest of the duct is sac-like, and the eiid sac shows the initial stages of
lobulation. This condition is carried further in PantlaZus, where long entl-
454
PROF. FI. GRAHAM USNNON A N D MISS S. &I. MANTON ON
sac lobes project into similar folds of the duct-wall, extending into an
other wise sac-like duct.
The connection between end sac und duct, as pointed out by Buri:in and
Mrith (1921, p. 642), is provitlcd in young stages of the Decnpoda with :I
v:~Ivesomewhat similar to the slriictures found in the Poracarida. Such a
valve, f i g u r d by Alluii (1593), for the yonng PaZ(Etnonetes, appears to bo
formed by the end-sac cells round the opening of the duct being very slightly
enlarged. No niuscular sphincter or fibrils such as occur in the Peracaric1:i
hnve been described. Burian and Muth point out that in the adult Decapod
this valve gives place in some cases to a similar functioning, hut less
conspicuous structure such as is found in Stenorhynczis. Here an :tccnmnlation of end-sac cells round the opening to the duct occurs, reducing the
size of this opening. This accumulation does not differ from the other
irregular thickenings of the multi-laminar end-sac wall. The cmhryonic
valves possessed by larval Decnpods referred to above are not nenrly so well
fortned as the similar structures in the Peracarida or the valve of the adult
Qennatlna. Thus, GennatEns appcnrs to be the ollly Decapod described
which has in the adult a well-developed typical valve between the o l d sac
and the duct.
The bladder system of the Decapod antenna1 gland develops as an outgrowth from the originally sitnple duct. We considor that mosi, of the
liomologies that have been drawn between the different lobes of the bladder
system in various types are of doubtful significance. However, Genriadas
certainly does show a hladder system that combines to a certniii extent the
characteridics found in both Caridea and Paguriclea. The anterior lobes
are cliaracteriatic of all extensive bladder systems, such as occur in the
(jaridea, Paguridea, rtnd Rrachyura. The transverse union between tho two
systems through the Inbruin is present just as in some Caridea, while the
posterior lobes may be compared to those of the Paguridea or, perliap.1, wit11
the paired or single epigastric lobes of the Caridea. A union between the
posterior lobes and a subintestinal lobe also occur in the I’aguriden. I t is
difficult to hoinologise the outer lobe marked (o.p.1.) in toxt-fig. 6 , C. It
inay reprewnt part of the posterior lobe of the Paguridea, which unites with
the paired or single l)lndders, :tnd which lies between the lobes of the
digestive gland or bctwecn the ovaries, or it inay bc a further developinent
of tho short unnnmed dorso-lateral lobe figured by Weldor1 in various
Caridea externnl to the nephroperitoneal sac (=epigaslric lobe) (1891,
plate xxi. figs. t & 3).
A consideration of the segmental excretory organs of the Mysidacea has
let1 us to suppose that the priinitive excretory glitnd of the Peracarida is
n type with n sitnple end sac anti a wide sac-like duct, and that the types
with narrow coiled ducis have been derived from the formor. W e consider
that a siinilar type of gland nlso gave rise to the conditions found jn the
THE SEGMENTAL EXORETORY ORUANS OF ORUSTAOEA.
455
Eucarida. The antenna1 glands of larval Decapods are of this type, and that
of the adult Hippolyte shows no great advance on this condition. The saclike duct has become longer, and almost completely envelops the end sac.
It is this tendency for the duct to envelop the end sac in the Decapoda
which distinguishes them from the Peracarida, and which partly led to the
development of the labyrinth, the initial stages of which are seen in
Gennadas. In the Perncarida the duct remains free from the end sac
throughout its course, and the end sac is lodged in a separate lobe of the
antenna1 base. The condition found in the Eupharisincea may be directly
TEXT-FIQ.7.
PRlMlTlVE
tIALACbSTRI.C/.N
PRlMlTIVF. PERACARIDAN
\
,
-
h
PRIMITIVF, LUCARIDAN.
c'
c.q Hipolyie.
;
!
\
'\,Pandalua.
I
LUPHAUSID.
COILED PERACARIDAN TYPE.
5
LABYRINTHINE MALACOSTRACAN.
Dingram summarizing the suggested evolution of the various types of antenna1gland
found in the Eucaridn.
derived from the Hippolyte type. The sac-like duct has only completely to
wrrtp round the end sac and its two extremities will come in contact. Fiision
of the duct-walls a t this point would give the ring-like duct. Them
suggestions are summarized in text-fig. 7.
Nothing critical can be said ae to the type of union between the end sac
and the duct in the most primitive type, and if R valve was present or
absent. It may not be without significance that in tho Euphausiacea and
LI".J0UBN.-ZOOLOQY, VOL. XXXVI.
37
456
ON THE LJEQMENTAL EXCRETORY ORGANS OF CRUBTACEA.
the Mysidacea with primitive glands (Heminzysis and Lophogaste?*) an
open coininuiiication between end sac and duct appears absent, wliile an
irregular group of cells, through or botween which sinall lacunar spaces
appear, is prevent a t the junction.
LITERATURE
LIST.
ALLIEN,E. J. 1893. Nephridia and Body-Cavity of some Decapod Crustncea. Q. J.
Microsc. Sci., London, ser. 2, vol. 34, pp. 403-436, with plates 20-28.
BURIAN
U N D MUTH1921, in WINTERBTEIN,
H. 1010-1926. Handbuch der Vergleichenden
Physiologie. Jena. Bd. 2, Hiilfte 2. 0. Cruetaceen, pp. 633-696 and text-figures
118-143.
CBUN,c. 1896. Atlantis. Riologische Sttidien iiber pehgische Organismen. zoolnpics.
Stuttgart. Bd. 7, IIeft xix. V.-Ueber pelagische Tiefsee-Schiropoden, pp. 1371Y0, with plates 8-16.
Onomm, C . 1801. Die Antennendriiae ron Leucyer rynnudii. Sitzber. Ak.Wiss. Wien,
Bd. 99, Abt. 1, pp. 669-ti67, with 1 plnte.
WELDON,W. F. R. 1891. The Rend Organs of certain Decapod Crustace&. Q. J.
Microsc. Sci., London, ser. 2, vol. 32, pp. 279-391, with plates 21-22,
ZIMMER,0. 1913. Untersucliungen iiber den inneren Bau voii Buphnusia superba Dam.
Zoologica. Stuttgart. Hft. 67 (=Bd. 26), pp. 06-128, with 7 plates and 6 textfigures.