Iconography on the abdominal cavity and viscera of
the Balaenoptera, with special remarks upon theperitoneal coverings
BY
T.rnAHIRO 0HE

Department of Anatomy (Prof. Dr. T. Ogawa)
Medical School, University of Tokyo.

In the baleen · whales the abdominal and pelvic viscera with the peritoneal
coverings have been seldom studied; only a few authors mentioned them in papers
concerning stomach, ovary and testis etc. Meanwhile H. von W. Schulte wasprobably the only one scientist who worked systematically upon this subject, when
he dissected a female foetus of the Sei whale. Recently I had the opportunity to
go into this problem by observing foetuses obtained on board of the factory ship,"Nissin Maru No. 1" in the Antarctic expedition in 1948-49. Following foetuses,
fixed with formalin, were examined with naked eye.
Serial Number

26
28
43

Speciffl

Sex

Body length

Fin
Fin
Blue

femalefemalemale

3 feet3 feet 5 inches
7 feet 8 inches

In the description I will. mention at first the general form of the alxlomina
cavity, dividing it for the sake of convenience into the preumbilical and thelpostumbilical region; illustrations of the relatively more simple constructed postumbilical region in both sexes will follow, and then the pictures showing the more
complicated preumbilical region will be added. Next each of the abdominal andpelvic viscera will be treated, laying stress especially on the peritoneal coverings
as well as on the topographical relations between the viscera and the parietal peritoneum. Bibliography will be noted at the end.

OBSERVATIONSI GENERAL OUTLINE
The lateral view of the abdominal cavity is schematically shown in Fig. 1, in
which the capacious preumbilical region :s more of a rounded form, whUe thepostumbilical region is narrow in dorsoventral direction. The narrowness of thelatter is due to the huge mass of longitudinal muscles, which lie ventrally to the

18

TADAHIRO 0HE

vertebral column, protruding considerably from the dors'.ll wall in this part of the
body. The postumbilical region is divided by a large peritoneal fold, plicaurogenitalis, or better to be called plica genitalis, as it is not concerned with urinary organ$, into two cavities, excavationes rectovesicales dorsalis et ventralis.1J

Anus

Fig.

I

The highest point of the abdominal cavity, that is, the locus, where thediaphragm.a reaches the most deeply into the thoracic cavity (Fig. 1, A), is at thelevel of 9. thor. vertebra, whiJ.e the lowest point of the thoracic cavity, where thediaphragma takes origin from the posterior abdominal wall (Fig. 1, B), is at theupper end of 3. lumb. vertebra (median) or the lower end of 4. lutnb. vertebra(laterally) and the point, where the diaphragma is attached to ribs median ventrally (Fig. 1, C), corresponds to the leyel. of 12. thor. vertebra. The caudal endof the excavatio rectovesicalis ventralis (Fig. 1, D) is at the height of 14. lumb.
vertebra:.
Actual measurements in No. 26 resulted; A-D 20.5 cm, the greatest breadth of
the abdominal cavity 8 cm, the greatest depth 7 cm, both at the level of the 2.
lumb. vertebra.
The black area in Fig. 1 denotes the abdominal cavity, the obliquely lined area
a portion of the· diaphragma which is projecting into the thoracic cavity, with theheart on its ventral slope and with the lungs on its dorsal. slope.
Fig. 2 shows the ventral view of the parietal peritoneum, muscles and fat
tissues entirely picked off. At the middle the cut surface of the umbilical cord isfound, having two arteries and two veins. Cranially to it and median, theumbilical vein is seen, two at first but soon they join into one. Caudally to thenavel there is the bladder with the umbilical arteries on both sides; besides, theliver, the intestines, and the plica urogenitalis are visible through the thin parietal
I) Although they are called " excavatio rectoµterina et vesicouterina " in the humananatomy, these names are not appropriate here, for the conditions in the whale are nearly
the same bet"·een male and female.

Ic-0nography on the abdominal cavity and viscera of the Balaenoptera

19

-

Liver

Plica
urogenitalis

Vesicaurinaria

A. umbilicalis

Fig.

2

_:;peritoneum of the anterior body wall.
Fig. 3 is a diagram showing a transection of the whal.e's body at the lower

20

TADAHIRO 0HE

part of the navel. Dorsally median, mesocolon is found, kidneys lateral to it, and

Fig.

3

Plica
diaphragmatica

KidneyBladdermore ventrolaterally a part of plica urogenitalis, which deserves here the name, plica
diaphragmatica, and the bladder lies ventrally median with the umbilical arteries.
The large muscles dorsal to the abdominal cavity and ventral to the vertebral
column is the above mentioned musculature which makes the postumbilical region
so narrow in dorsoventral direction.
II POSTUMBILICAL REGION
No definite boundary is to determine between the pelvic cavity and the otherparts of the abdominal cavity, and the kidneys cause remarkable prominences on
the posterior abdominal wall. In both sexes the large peritoneal duplicature, plicaurogenitalis, rises from the lateral wall corresponding to the height of the upper
end of the kidney and extends mediocaudally and ventrally to the kidney, forming
the plica diaphragmatica; both halves, left. and right, of the fold join together

Iconography on the abdominal cavity and viscera of the Balaenoptera

21

at the lowest level of the kidney, and form the so-called p!ica lata, which divides
the cavity completely into two excavations already mentioned. Of .them the excavatio rectovesicalis ventralis, which contains the bladder is small, while the excavatio rectovesicalis dorsalis is elongated with the colon passing in it. The plicaurogenitalis shows remarkable sexual. differences.
(I) In the female.
Fig. 4 represents the female pelvic viscera in situ, the parietal peritoneumdeprived off. Cut surfaces of the bi.adder and of the umbilical artery are visible

Plica
diaphragmatica

KidneyChordauteroinguinalis
Plica lata

Bladder

Fig.

4

22

TADAHIRO

ORE

in the caudal part. The ovary is attached dorsally to the plica diaphragmatica
hear the lower margin of the kidney. At the upper edge of the plica lata theuterine cornua and the oviducts are seen. The plica lata is thick and not sotransparent, that the uterine corpus and ovary can not be seen through. On theplica lata we see a pair of thick .bands ( chorda uteroinguinalis == lig. teres uteri)iunning caudad from the distal end of the uterine cornua.
Fig. 5 shows a part of the plica urogenital.is seen from behind; only the righthalf is drawn. After making a ventral curvature, the uterus continues to theoviduct, which is short, thin but remarkably wound, lying a little lower than theborder of the mesosalpinx and the part of the peritoneum more distal than the
Fig.

5

Plica
diaphragmatica
Ostium abdominale--

Ovary.

Chordauteroovarica

abdominal aperture of the oviduct is folded, forming a ligament. 2). In Fig. 5 thisligament is partial.l.y cut to make the ostium abdominale visible, but no fimbriae
are seen. The chorda µteroovarica ( == lig. ovarii proprium) runs from the plica
lata to the medial central part of the ovary. The right ovary is situated a little
higher than the left.
To show this part more ctearly, the transverse sections passing through theovary and just above the union of uterine cornua are illustrated in Fig. 6 A et B.
In A the ovary is found attached dorsal.ly to the plica urogenitalis by means of2) Ommanney noted this ligament and the wavy course of the oviduct is illustrated wellin the paper of Beauregard et Boulart (1882).

Iconography on the abdo~ninal cavity and viscera of the Balaenoptera

A. umbilicalis

23

ventralt

Bladder!
dorsalA

Chorda uteroinguinalis

Ureter

v
B

Aorta
Fig.

6

mesoovarium and in B the thickness of the plica lata and of the chorda uteroinguinalis are indicated..
(2) In the maleFig. 7 shows the postumbilical region in the male. The plica diaphragmatica
suspends the testis at the height of the caudal end of the kidney. The epididymis
is seen cranially to the testis and the vas deferens runs caudad, lateral to thetestis and between them a deep furrow, sim1s epididymidis, is formed, beingbounded by a peritoneal fold on the side of vas deferens. The vas deferens isbent mediad, dorsally to the mesorchia~us of Esclfricht ( =:' gu_bernaculum testis?), astrong cord running from the testis on the ventral surface of the plica lata, andconverges from both sides in this peritoneal fold to open into the urethra.
Fig. 8 shows schematically the relationships between plica urogenitalis, testis,

24

TADAHIRO 0HE.Epididymis

Vasdeferens

Fig.
Kidney

7
Colon

Plica
diapb.ragmatica

TestisVasdefetens

Plica lata
M:esoorchiagus

I·

Ureter Bladder A. umbilica!isFig. 8

Iconography on the abdominal cavity and viscera of the Balaenoptera

25

epididymis and vas deferens.
The dorsal surface of the plica diaphragmatica is smooth; strong fibres areseen at the edge of this fold and at the caudal end of testis. Fig. 9 is a diagramof this part, cut near the middle of testis.

ventraliA. umbilicalis

Vas deferens' UreterdorsalFig. 9(3) Excavatio rectovesicalis dorsalis
Fig. 10 shows a longitudinal section of the dorsal excavatiO rectovesicalis. The
rectum, except its small portion near the anus, is cut off but the mesocolon remains.
From ventrally the bladder, the urethra, next the uterus and vagina are recognized
Bladder

Vagina Urethra Clitoris

Mesocolon Aorta
Fig.

10

Anus

Rectumand the abdominal cavity reaches very deeply near the anus. At the left side of, this figure a diagram of the transectioned outline of this area is added.

26

TADAHIRO OHE .

III PREUMBILICAL REGION
As to this region, no remarkable sexual difference is ascertained.
In Fig. 4 the ventral mesohepaticum ( = lig. falciforme hepatis) is cut off and
two umbilical veins unite into one before they enter the liver. The large liveroccupies the upper part of the abdominal cavity and the small intestine, forminga mass, lies. under the left. hepatic lobe and extends from here to the right andContact
area
betweendiapbragma
and liver._

2. chamberof stomach

Rightadrenalbody

Rightkidney ........ ---Omentummajus---------Leftkidney.. ____ ---·---·Colon-- ------------- Plica lata

Fig.

11

Iconography on :he abdominal cavity and viscera of the Balaenoptera

caudal direction upto the umbilical region.

27

The hepatic parenchyma is so fragilethat we can easily pick it off with pincette, leaving only the capsule.

Thefragility seems to be due partly to insufficient fixation as I did not inject any
fixing fluid intravascularly.
In Fig. 11 the plica urogenitalis and the hepatic parenchyma are taken off.
The hepatic capsule is cut along the line, where it reflects upon the diaphragma
and turns to the lesser omentum. The liver is adhered in a square form to thediaphragma and also to the 2. and 3. chamber of stomach, and to the pancreas.
The lesser omentum is very small and no foramen epiploicum is present.

The

right lateral mesohepaticum ( = lig. triangulare hepatis) does not exist distinctly,
while the left lateral one is slender but well developed,. courses at first laterad,next caudad.

The 2., 3. and 4. chamber of stomach (the fourth chamber isnothing but the duodenal ampulle) come into sight and the small intestine hitherto
conceale:l by the 1.eft hepatic lobe can be seen,. its mass extending from left cranial
to right cau.dad and nearly half of it being envelopped by the larger omentum.
The larger omentum, originally situated between the stomach and the mass of thesmall intestine, is artificially stretched to show its whole extent.

The kidney is

proportionately very large; to the relatively higher located right kidney is attached
the right adrenal body.

In the caud.il part the colon is seen running downwards

between both kidneys and we see here the cut surfaces of uterus and plica lata.
By obliteration of the foramen epiploicum the omental bursa is all over closed
and the larger omentum retains its cavity, bursa omenti majoris.

Now the larger

omentum is cut at its entrance, hiatus bursae. omenti majoris, and the small
intestine is for the greatest part taken off, cut at the duodenojejunal flexure andjust before the ileocaecal transition, leaving the radix mesenterii.
also cut off.

The kidneys are

Fig. 12 was drawn from a little left side. We see the attachment of

the larger omentum to the stomach, but not its attachment to the pancreas, owing
to the presence of colon.

The caecum is located at the height of umbilicus.

Thecolon ascends on the ventral surface of the mesentery, and without any definite
transverse portion, descends then on the dorsal surface of the mesentery.

The

left adrenal body is locate:i apart from the kidney, dorsally to colon descendens.
In Fig. 13 the colon is cut off, and the stomach is lifted a littl.e. ·The ascending colon is adhered to the pancreas and the lines of origin of the larger omentum
from stomach and pancreas are clearly seen. The duodenum, continuing from theampulla duodeni, descends and turns to left around the caudal end of radix
mesenterii, then runs further transversally and ascends dorsally to reach theduodenojejunal flexure.

; .

28

TADAHIRO 0HE

SecondchamberFirst
chamberof stomach

ThirJ
chamber

Spleenr,eftadrenalbody
Radixmesenterii
Caecum---- --- -·- - -Colon - - -----------Contact
area
betweenthe right
kidneyand theposterior
body wall

Contact
area
betweenthe lett
kidneyand thepcsterior
body wall

Fig.

12

In Fig. 14 all chambers of the stomach are taken off; we see now the total ventral
aspect of the pancreas.. The 4. chamber is cut at its junction with duodenumtransversum and the colon is cut just proximally to its adhesion to the pancreas,so that a part of the colon remains attached to the pancreas. As the inferior vena
cava penetrates deep through the liver, its sectioned surfaces, cranial and caudal,
are seen and on the left side of its caudal cut is the area where the 1. chamberof stomach is attached to the diaphragma and at the middle of this area we see
the end of the oesophagus. In the pancreas, tuber omentale is strongly formed andIconography on' the abdominal cavity and viscera of the Balaenoptera
2. chamber

3. chamber

Fig.

29
13

I

the cut surface of the portal vein is visible, appearing from behind the pancreas,
to enter the liver. The part of the pancreas left to tuber omentale is its corpus,
which makes a part of the dorsal wall of the omental bursa, and the cauda of thepancreas is directed dorsad. The part left to tuber omentale is of a small triangularform, faces also to the omental bursa from behind and the caput of pancreas slopes
dorsad at the right side of tuber omentale; the 4. stomachal chamber is adhered tothe caput.
Fig. 15 shows the posterior body wall itself, almost all of the viscera deprived
of. The area of attachment of the liver and of the 1. stomachal chamber to thediaphragma is naturally the same as in the former figure but caudally to the areaof the 1. stomachal chamber there is a place, where the cauda of the pancreas is
attached to the diaphragma. And the inferior vena cava passes behind the middleof the pancreas area. The mesoduodenum is, after the caput of pancreas has disappeared, is directly broadly adhered to the posterior body wall, bending transversad caudally to it and disappearing at the pancreatic cauda area, where theduodenojejunal flexure lies. Scarcely any mobility of the duodenum can be assumed•30

TAL'AHIRA 0HE

Pancreal3
Corpus~-

---

Tuber
omentale
Capnt • - - - -

1(1'/

,'
Duo:lemnn'

V. mesenterica
Fig.

Radix inesenterii

14

from the broadness of mesoduodenum. The mesocolon is situated left to themeso::luodenum ascendens and ends at the pancreatic cauda area, for it is adhered
to ·the ventral surface of radix mesenterii. The part between the pancreas-area
and the mesoduodenum-area is radix mesenterii and there the cut ~nd of themesenterial artery is seen. The right adrenal body lies partially concealed by thepancreas.
Fig. 16 shows the stomach already illustrated in Fig. 11, but viewed from
more right and ventral .direction. The 2. and 3. chamber are adhered to the liver
and the 4. chamber to the ventral surface of the pancreas. The part of thehepatic capsule which faces to the omental bursa, that is, th".! free surface of thepapillar process is taken off, so the pancreatic corpus can be seen and the upper
border of the pancreas in thi_s figure is the entrance to the .bursa of the larger.omentum.

Iconography on the abdominal cavity and viscera of the Balaenoptera

Fig.

31

15 (a)IV REMARKS UPON EACH ORGAN
In this chapter, the abdominal and pelvic viscera will be described, especiallyin relation to the peritoneal covering. In the following figures the white area
always means the part covered with peritoneum, the oblique-lined area the portion
adhered to other organs or to the body wall, the dotted area the part facing tothe omental bursa.
(1) Liver (Fig. 17)"It occupies nearly all of the upper ab:lominal cavity, its right fobe is· verylarge, but the left lobe extends more caudally_ and covers from ventral the massof small intestine, stomach and upper part of the left kindey (Fig. 4); so we caneasily recognize on the dorsal surface of the liver, hollows caused by stomach,
duodenum, intestine and kidney.

As t~e inferior vena cava is entirely embedded

into the liver, the caudate lobe can not be discriminated and the right . and the .left
lobe of the liver are directly continuous in the dorsal part. Only the papillar
process is well develope1 and adhered ventrally to the 2. and 3. stomachaL chamber

32

TADAHIRO 0HE__ V. hepatica

V. cavacaudal is- -V. mesenterica

Leftadrenal bodyj;.;.;.:j~~§lIIfI11

Conracr area between liver and diaphragma0""pancreas ''''duodenum '' "sromachRadix mesenreriiFig.

15 (b)and the dorsal durface of its base is attached to the pancreas so that it is nearlyencircled with stomach and pancreas, projecting into the omental bursa between
them. We see neither the quadrate lobe nor the gall bladder. The ventral mesohepaticum broadens from the point where the inferior vena cava passes throughthe diaphragma, to which the liver is attached in a squai:e form.
(2) Pancreas
Fig. 18 shows the relation of the pancreas to other organs. The area, where
it is attached to posterior abdominal wall, is finely oblique-lined, while the areaof its attachment to other organs is roughly oblique-lined .. The pancreas is situated dorsally to stomach and duodenum, cranially to colon and almost parallel toIconography on the abdominal cavity and viscera of the Balaenoptera
Ampulla duodeni.

I

I
Fig.

Pancreas

Fig.

17

16

33

. TADAHIRO 0HE

34

ventralv1ew

caudalv1ew

V. rn.

V. P·\T. l'·

V.m.

cranial-view

dorsal-view
V. p. V. portae
V. m. V. mesenterica

Fig.

18 Pancreas

Iconography on the abiominal cavity and viscera of the Balaeuoptera

35

these organs~ it is elongate:l fto:n left cranial an:l dors'lr towards right, ventrad
and caudad. Its form is ellipsoid in the ventro:lorsal direction and nearly tiian·gular, seen from a vertical plane to its long axis. The caput is more expanded
than the ampulla duodeni, which is located more ventrally; so its peripheralborderbas the peritoneal covering. The processus uncinatus is small. The cor!Jus, which
is near the caput triangular in shape, and more left of a square form, makes apart of the dorsal wall of the omental burs'!. The boundary between caput and{;Orpus, is remarkably prominent ventrad, tuber omentale, and in some specimens
goes into the liver along the p~rtal vein. The caudal margin of the corpu~ isadhered to the colon. The cauda is bent dorsad, .and mark together with the 1.
{;hamber of stomach the leftmost portion· of the omental bursa. Between this area
and that, where colon and pancreas are attached, there remains a small area{;overed with peritoneum. The pancreas of Fig. 18, -:Seen from ventrally, is the· same as that of Fig. 15 and the figure seen from cranially shows the pancreas inFig. 16, the stomach being omitted here. ~e figure seen from caudally corresponds to Fig. 13 viewed from almost horizontally. The veins coming from theintestines make deep furrows on the back of the pancreas and participate in theformation of the portal vein along tuber omentale.
(3) Stomach and duodenum (Fig. 19)
The abdominal part of oesophagus, between diaphragma and stomach, is rather
long and the dorsal surface of 1. stomachal chamber is adhered to the diaphragma
in a wide area. The 2. and 3. chaip.ber are extended obliquely from cranial left
to caudal right, and on the right side they are attached to the liver, pancreas andthe basis of proc. papillaris. The 4. chamber, that is, ampulla duodeni, is adhered
to the pancreatic caput dorsally and the duodenum changes its course abruptly at
the radix mesenterii and ascends behind this and continues to jejunum.
( 4) Bursa omentalis
By the lost of foramen epiploicum the omental bursa, the capacity of which'is small, has no opening. It is surrounded by 1., 2. and 3. stomachal chambers,.cauda and corpus of the pancreas and divided into three portions. The attachment of pancreas to the posterior body wall and to the liver causes the absence.of vestibule and of superior recessus in the omental bursa. The µapillar process
is projecting into it, particularly into the area between the 2. stomachal chamber.and the p'lncreatic corpus. The peritoneum covering the stomach turns· over to.the pancreas at the boundary between 3. and 4. chambers of stomach, just craniallyto the border of the pancreas where it is attached to colon and it passes to 1.
.stomachal chamber from the pancreatic cauda and, bending near the spleen,

36

TADAHIRA 0HE

returns to its original point. Caudally from this hiatus extends the bursa omenti
majoris.
(5) Small intestine
The coiled mass of the small intestine is in the upper abdominal cavity,
specially in the left side as if its more caudal development were prevented by thedorsal-view

ventral-view

Fig. 19 Stomach

presence of kidneys. The long axis of the intestinal mass is directed from left
cranial to right caudad and its upper 2/3 is covered by the left hepatic lohe. No
rest of the ductus omphalomesenterica (Meckel's diverticle) is seen.
(6) Colon
The caecum is located in the right side nearly at the level of the umbilicus
and the mesocolon ascendens is adhered to the ventral surface of radix mesenterii
and the upper part of the colon is adhered to the pancreas. The colon bends atthe cranial end of the radix mesenterii dorsad and descends dorsally along theradix mesenterii, and so the mesocolon descendens rises from the posterior bodywall. Passing between both kidneys, it descends into the ·dorsal excavatio rectovesicalis. No transverse. portion of the colon is discernible and the whole colon isin a plane directed sagittally, that is, dorsoventrally rather than frontally.

Iconography on the abdominal cavity and viscera of the Balaenoptera

37(7) Spleen
The spleen, attached to the outer surface of 1. stomachal chamber, is relatively very small and except this area of attachment it is covered all over with peritoneum. Dorsally a strong Iig. gastrolienalis is found.
(8) Adrenal body
The right adrenal body is attached to the right kidney and located between
kidney, liver and duodenum, concealed partially by pancreas. The left adrenal
body is tolerably distant from the left kidney and near the colon descendens aboutat the same level of the right one.
(9) Kidney (Fig. 20)
The voluminous kidney is seen directly by taking off the parietal peritoneum.
And through its capsule numerous renculi are found. The right kidney is located

left

left

ventral-view

dorsal-view
Fig.

20

a little more cranially. The area where the kidney is attached to the posterior
body wall is broad, its cranial, lateral line is concave. The areas faced to theliver, small intestine and plica urogenitalis are easily recognizable. The hilus

3S

TADAHIRO 0HE

exists at the upper end, wher~ the blood vessels enter the kidney and it is at thecaudal end that the ureter leaves. Moreover, laterally between the lateral bodywall and the kidney two peritoneal folds are formed, bringing forth some recesses3l,
the caudal one of which is just above the origin of the ureter.
(10)

BladderIts dorsal surface faces to the abdominal cavity and near its cranial portion it
bulges with its peduncle, but the more caudally, the less it is prominent into theabdominal cavity.
LITERATURE
l' H. von W". Schulte; Arnitomy of a Foetus of Balaenoptera borealis.

American Mmieum of Natural History.

Memoirs of the
New Series, Vol. I, Part VI, pp. 389-502.

2 Ommanney, F. D.; The urino-genital system of the.Fin whale.
v, pp. 363-466, 1932.
3 Weber, M.; Studien iiber S:iugetiere.

Discovery Report, Vol.

Jena I, 1886, pp. 66-77. II, 1898, pp. 6G-63.

4 Beauregard, H. et Boulart; Recherches sur les appareils genitourinaires des Balaenides.
Jour. de l'anat. et de la Phys. An. 18, 1882.
5 Daudt, W.; Beitriige zur Kenntnis des Urogenitalapparates der Cetaceen.
Zeitschr. f. Naturwiss., Bd. 32, 1898. s. 231-312.
6 Jungklaus, F.; Der Magen der Cetaceen.
s. 1-94.

J enaische

Jenaische Zei1llchr. f. Naturwiss., Nd. 32, 1898,

7 Ivar Broman; Colom. Handbuch der ver6leichenden Anatomie der '117irbertiere, Vol. III,1937.
8 Ellengberger und Baum; Hnndbuch der Vergleichenden Anatomeie der Haustiere, 16. Aufl.,
1926.
9 Carte;' A. and Mac Alister, A.; On the anatomy of Balaenoptera rostrata.
Roy. Soc. London, Vol. 158, 1871.

Phil. Trans.

10 Meek, A.; The Reproductive Organs of the Cetacea. Journ. Anat. London, Vol. LII, pp.
186-210, 1918.
11 Ping, Chi; On the Testis and its accessory structures in the Porpoise (Neomeri'l). Anat.
Record, vol. XJL"CII, No. 2, p. 113, 1926.
12 Ping, Chi; On some parts of the Visceral Anatomy of_ the Porpoise (Neomeris phocaenoides). Anat. Record, Vol. XXXIII, No. 1, p. 27, 1926.
13 Hunter, ,John; Observations on the structure and economy of_ whales. Phil. Trans. Roy.
Soc. London, 1787.

14 Rapp, W.; Die Cetaceen. Stuttgar~ u. Tiibingan, 1837.
15 E'3Chricht, E.; Zool.-anat.-phys.
1894.

Untersuchungen iibe.r '.die nordischen Waltiere. Leipzig,

16 Anthon~, R.; Recherches anatomiques sur l'appareil genitourinaire male du Mesoplodon
3) These folds are well il:ustrated in the figure of W. Daudt (1898).

Iconography on the abdominal cavity and viscera of the Balaenoptera

3!t

et des Ceteaces en general, Mem. Inst. Esp. Oceanogr. Madrid, 3 mem., 2, pp. 35116, 5 pls , 64 text-figs.
17 Perrin, J. B.; Notes on the anatomy of Balaenoptera ro.strata. P. Z. S., London, 1870.
18 Yves Delage;; Histoire du Bal. musculus echoue sur la Plage de Langrune. Arch. de ZooL
exper. et gen., Deuxieme Serie, T. III, Paris 1885.
20 Beauregard et Boulart; Sur l'utricule prostatique et les canaux deferents des Cetaces.
Compt. rend. de l'Acad. des Sc., T. CXVIII, Paris 1894.