nil i-m.-K.i. 





t arises as tii> lied eardi 



diverticula jttom ou1 from the walla of this tub< 



In t he comparath ely simple 

 siti" the auric 



more or less <\ idenl e\ en in the full 

 in 1 1 1 • - the auricli - 1 1g i' 1 ; bul in t li- 



mammalia it is impossible bj superficial examination 

 remains of the primith iia<- tub< M 



ti"»ns duri have, ho show n thai il 



jtructu I of t i 



nt from that of tlr irt, and d 



TH 







as would indicate n<>t onlj thai it is derived from 



tube, bul ;iIm> thai it is the main pathway which 



transmitted. 



I his primil much ; 



giona than in others, 1 1 * • - firsl portion 

 known ;is the of S 



This Btructui >und .it ti 



ttiin on the riu'lit Ride and 

 of peculiar small primitive cells and fil 

 a bum iliar t. 



w here, near the union of the • 







