299 



whether there is nervous connectioa between them or not. Later 

 stages, however, show that there is none. 



Fig. 2, stage 32, shows that the epiblastic ingrowth has become 

 separated from the skin, and a lumen is beginning to develop in it. 

 It is still in connection with the pharynx by a thick solid strand of 

 hypoblast. Throughout development the strand of hypoblast is solid 



Hind Braio 



VII2 



Hyo 



L.L.O. 



Fig. 1. Stage 31. Zeiss A. 4 oc. Abbe Camera. Section transverse to the 

 body through the spiracular rudiment. Ej) Epiblastic j^ortion of spiracular rudiment. 

 Gang. VII Facial ganglion. Ilyo Hyoideomandibular nerve, the lateral line component 

 of which is running to L.L. 0. rudiment of a lateral line organ. Ph still solid nidiment 

 of the Pharvnx. 



except at its inner end where in later stages the lumen of the pharynx 

 extends into it for a very short distance. 



A slightly later stage is shown in the reconstruction in Fig. 3. 



In stage 35 (Fig. 4) the connection between the developing organ 

 and the pharynx is no longer complete, being broken through close 

 to the pharynx. The greater part of the former connection, however, 



