M. [Lssow's Zi>olo(jlco-Eiid>riji>liii]ii-nl I nn stl(j(iliiins. .'Hi* 



inversion ot" the upper hunclla. In tlic t'ornier case the upper 

 laniellii fre(pientlj plays the part of a thin external envelope 

 to the rudimentary organ, consisting ot" the dernio-niuscular 

 or intesti no-fibrous layer ; or it sj)lits into several layers, the 

 lower ot which form the organ proper. In the second case 

 the upper lamella forms various de])ressions at different parts 

 of the germinal disk, and [)enetrates into the middle lamella, 

 which thus forms the envelope of the organ. 



The following Table furnishes a sumniary of the mode of 

 appearance of each o)-gan : — 



As regards the stomach (and also the so-called crop), the 

 caicum, and the liver, these are secondary formations, origi- 

 nating from dilatations of the original intestinal tube ; the 

 salivary glands and tiie so-called branchial hearts must also 

 be reckoned ."secondary organs. 



