168 MR. E. W. SHANN ON THE EMBRYONIC 



course, ei-roneous ; it arose through my having been content to 

 dissect a specimen whose stomach had already been punctured.) 

 Anteriorly the cardiac stomach tapers somewhat abniptly to the 

 wide opening of the oesophngus. The latter organ is thick-walled 

 and its lumen is longitudinally ridged ; it communicates freely 

 with the pharynx. Leaving the cardiac stomach in the region of 

 the posterior third and slightly on the right side a narrow, but 

 very muscular, tube runs forwards to enter the anterior end of 

 the spiral intestine close to the point wliere the oesophagus 

 debouches into the stomach. This tube is undoubtedly the 

 pyloric portion of the stomach ; it opens by a minute tunnel-like 

 aperture into the cardiac portion, in whose wall it is embedded for 

 some distance. The lumen, though minute, is nevertheless con- 

 tinuous from the cardiac portion to the spiral intestine. The 

 latter organ is fully developed and passes posteriorly into the 

 short rectum, Avhich bears the characteristic dorsal diverticulum. 

 The spleen is well developed (this is the " lobed tissue" whose 

 significance I was unable to determine in my former paper). 

 The pancreas is smaller and does not appear in the illustration, 

 since it is situated on the left side. The liver is of large size and 

 typical shape ; it communicates by a,n apparently functional bile- 

 duct with the apical intestine, entering it from the ventral aspect 

 elo.^e to the pyloric opening. 



In the youngest specimens examined by me (F) the muscles of 

 the head presented a curious condition. The normal muscles (e. g., 

 constrictor, coraco-mandibnlaris, coraco-hyoideus, and coraco- 

 bvanchiales) were recognizable, but instead of being composed 

 of well-defined masses of compact muscle-fibres, the fibres were 

 few in number aiid embedded in a mass of gelatinous non-cellular 

 material. In older specimens this gelatinous matter gives place 

 to true fibre : the process is correlated with considerable shrinkage 

 in the relative girth of the head of the embryo. 



There are five pairs of different branchial arteries, as figured 

 and described by Lohberger. My previous description of six pairs 

 I now consider to have been due to an error in dissection, for I 

 have found only five pairs in the specimens examined since my 

 first dissection was made. 



V. Physiology of Nutrition. 



The cardiac portion of the stomach (yolk-stomach) contains a 

 mass of pa,le yellow-coloured pulp. The latter is finely granular as 

 seen under the microscope; I failed, however, to find the dumb- 

 bell-shaped granules described by Lohberger. The pulp is not 

 uniform in consistency, for intermingled with it are irregular 

 aggregations of skin-like matter, which Lohberger regards as 

 portions of egg-membrane; indeed, he states that Swenander 

 found two entire egg-capsules in the yolk-stomach of a 30 cm, 

 specimen. 



