BiidMAN und RiETz, Verdaiiungsrohr. -ng 



„The Said eidarifement of the ductus communis clioledochus extends as a small c u 1 - d e - s a c baci^wards froni where 

 it first penetrates the serous intestinal coat; and tliis portion of it is smooth-wallcd within; but furthcr oii, as it narrows, 

 it becomes transversely trabecular. Though relatively capacious, this Inflation of the intestinal portion of the bileduct is not 

 j)eruliar and alone met with in the Walrus, as stated by Home." 



„The pancreas is large, broad, and flat an with the usual glandulär structure, of a yellowish or cream-colour; the 

 duct as mentioned i)." 



„The mesenteric and abdominal lymphatic glands, as in the Pinnipedia generally, are numerous and of considerable 

 dimensions; and within the folds of the mesentery exceedingly large lymphatic vessels are displayed. Indecd thesc Ivni- 

 phatic Channels, convergent from the intestines towards the glands, are a remarlvable feature, so distinct and large are they. 

 riiysiologically it may be inferred that assimilation is very rapidly eflected in the Wah-us, as doubtless is the case in the 

 Seals, also fish-eaters, and equally remarkable for their voracity and speedy digestion" (1. c. p. 429). 



„Little appreciable difference is exhibited throughout the Pinnigrades in the construction of the alimentary 



canal. It is simply that of a Carnivore, with, howcver, a moderate-sized coecum. The great glandulär superficies and cor- 

 related large lymphatics point to means of speedy and frequent digestion; and in the Wakus these apparatus are extra- 

 ordinarily devcloped." 



II. Descriptive Anatoiii.v of the Sea-lion (Otaria jubata). 



Alimentary Ca n a 1. 



a. Relative p o s i t i o n s o f the Abdominal V i s c e r a. — A longitudinal median iiicision having been 

 niade into the abdomen from the ensiform cartilage to the pubis, the contained viscera were found disposed in the under- 

 noted condition. The Liver, which occupies both the right and left hypochnndriac regions, was not seen to dcscend or come 

 posteriorly further than the ensiform cartilage. This viscus was equally divided into right and left moieties by the falciform 

 hgament and the remains of the foetal vessels. The stomach was barely visible, being situated deeply in the left hypochon- 

 driac region, and almost entirely hidden by the liver. The great Omentum, in the present instance perfectly devoid of fat, 

 thiu and quite transparent, did not, as is most commonly the case in Carnivora, cover the intestines, but was partially sunk 

 aniong the folds of the gut. Nearly the whole visible Contents of the abdomen seenied to be occupied by the small in- 

 testines; only a small portion of the rectum peered out behind them and towards the right iliac region. The empty and 

 contracted urinary bladder extended forwards no great distance beyond the Symphysis pubis. The eaecum, firmly attached 

 to the mesentery, lay towards the right side of the spine and between the ensiform cartilage and pubes, being rather towards 

 the former. From the eaecum the great intestine runs backwards to the iliac region, forms a loop and returns forwards 

 again; then, with only a partial transverse fold, reaches the left of the spine, lying at this part behind the unusually loose 

 kidncy. Above the superior fundus of tlie bladder its rectal fold directs itself towards the median line, and passes into the 

 pelvis, at first rather to the right side of tlie bladder. 



b. The Oesophagus. — Taking this wide tube as commencing at the lower border of the inferior constrictor 

 nniscle, it measures from this to the eardiac orifice of the stomach 22i'2inches in length. In the contracted condition its 

 nuicous membrane is tough and elastic, and thrown into very mmierous interlacing and strongly ridged, pale-coloured, longi- 

 tudinal pUcae. The submucous areolar tissue is plentiful, and the muscular coat very strong and thick. 



The thick, well-dcveloped nuiscular coat of the Oesophagus of Okirid afforded nie ample opportunity of testing whethcr 

 its conqiosition was similar or otherwise to what Dr. Rutherford has described in the guUet of the Sheep, Ox and üog. 

 According to hini, layers of fibres cross obhquely hke tlie letter X, but are not continuous Spiral fibres from pharynx to 

 stomach — rather decussating in eveiily distributed bundles or loops, which form short parallelograms crossing three times. 

 Thus, while strength and rapidity of transmission in either direction is gained, the tube retains a more or less uniform thick- 

 ness of wall. I find, therefore, after tracing the fibres with great caution, in the hardened and distended guUet of this Seal, 

 that they perfectly correspond with the structural conditions extant in the Ruminants and Carnivore examined by him. Iiideed 

 it becomes evident, on consideration, that the diverse direction and iiiterdigitating of the lleshy fibres of the three massive 

 constrictors of the pharynx are, whith some modification, modelled after the same fashion. Those fibres at the opposite 

 extremity of the tube, iiear the eardiac orifice, are thicker than at the middle of the gullet, and they pass on to the stomach, 

 tending to form the socalled constrictor or oblique bands of the eardiac eiid of the stomach. The deep layer of fibres has 

 the greater obliquity of the two. 



CuviER's and Meckel's observations (unnoticed by Rutherford) though indefinite as regards the length and conti- 

 nuity of the spiral fibres, show at least there is a common type of structure prevalent amoiig several Orders of Manimalia, 

 quite irrespective of ruminating-power. 



') Wo er dies früher er\vilhnt hat, habe ich aber nicht finden können. 



Deutsche Sildpolar-Expedition. XIV. Zoologie V[. 65 



