ON EMBRYONIC DIFFERENTIATION 267 



importance. The process here referred to is that of 

 admixture, of the raw alimentary materials, with the 

 lymphoid and colloid excretionary juices, exuding con- 

 stantly from the fauces and tongue, and consisting of 

 the pituitary excretion from the structures known as the 

 tonsils, lateral and central, the uvula, and the whole extent 



FIG. 113. DIAGRAM OF THE ABDOMINAL PART OF THE ALIMENTARY 

 CANAL. (Brinton.) 



c, the cardiac, and p, the pyloric end of the stomach (this organ is represented in too 

 horizontal a position) ; D, the duodenum ; j, i, convolutions of the small intestine; 

 cc, caecum, with the vermiform process ; AC, ascending, TC, transverse, and uc, 

 descending colon ; SF, sigmoid flexure ; K, rectum ; A, anus. 



of the glosso-pharyngeal mucosa (see Figs. 100, 112). 

 It will, we think, become apparent, more and more, as 

 investigation of the subject progresses, that we have here 

 to deal with digestive factors and problems of no mean 

 importance arising from the physical admixture and 

 resultant chemical action and reaction of two very dis- 

 similar sets of substances, viz. of the excretionary, or 



