3^8 DRS HEPBURN AND WATERSTON ON THE 



yet, in his plate, Jqngklaus figures several stomachs of foetal porpoises which apparently 

 entirely agree with our description of the adult stomach. 



We are therefore forced to conclude that, by our method of preservation, we have 

 been able to retain the normal appearances and shapes of these stomach chambers, 

 which have hitherto either been lost, or of such uncertain characters as to lead to error 

 or difficulty in the determination of their true homologies. 



(6) The fourth compartment, being tubular or cylindrical, is distinctly marked off 

 from the spherical third chamber on the one hand, and from the duodenum on the 

 other. The acute bend near the middle of this chamber, and the pre-pyloric dilatation 

 (Antrum pylori), show how readily it might be still further subdivided. 



(7) From these considerations, it would seem as if the stomachs of all cetacea were 

 constructed upon a common plan of subdivision into a series of chambers, with such 

 variations as regards the number, size, and particular shapes of the compartments as 

 are explicable by reference to the porpoise, and are probably due to differences in the 

 characters of the teeth and the nature of the food determining the presence or absence 

 of that particular compartment which we have called the "kau-magen" or masticatory 

 stomach, and which in the case of the porpoise forms the first of the series of compart- 

 ments. Further, the homologies of these compartments among different members of 

 the Cetacea should be established by their structure and anatomical relations rather 

 than by numerical sequence. 



(8) We regard the duodenum as that dilated part of the alimentary canal between 

 the pylorus and a point immediately beyond the common entrance of the bile and 

 pancreatic ducts. 



(9) Intestine proper commences at the termination of the duodenum, and is sus- 

 pended throughout in the mesial peritoneal mesentery. 



(10) The small size of the spleen is probably compensated for by the unusual 

 amount of lymphoid tissue distributed in the omentum and at different parts in the 

 wall of the alimentary canal, especially towards its lower end. 



(11) Throughout the entire length of the alimentary canal, villi were absent. 



LITERATURE. 



The literature on the Cetacean Stomach is very extensive, but it has been brought up to date by Dr 

 Friedrich Jungklaus, who quotes 63 memoirs in his paper " Der Magen der Cetaceen," Jenaische Zeitschrift 

 fur Naturwissenschaft, xxxii., 1898. 



Lehrbuch der Vergleichenden MifcrosJcopischen Anatomie der Wirbeltiere, Oppel (Jena), 1896. 



