278 



panying figures. Fig. 1 is a dorsal view of the ciliated funnel duct 

 and gland; Fig. 2 a view of the same structures from the right side; 

 Fig. 3 is a sagittal section of these organs in a well developed bud of 

 Botryllus. (The slight difierences between these organs in the im- 

 mature condition and in the adult need not occupy us here.) 



At a glance one sees that the duct runs up dorsal to the ganglion 

 and connects with the dorsally-placed gland. The point where the 

 duct joins what we may properly call the glaad is difficult to deter- 

 mine. The funnel narrows into a duct which enlarges some distance 

 in front of the ganglion into a large chamber with thin walls (Figs. 1, 

 2 and 3 gl'). This extends back to about the middle of the ganglion 

 where it again narrows into a small tube, which runs on over the 



Fig. I 



cf 



ph 



FlQ II 



ph 



Fig. 1. Dorsal view of ganglion and neural gland in Botryllus Gouldii. 



Pig. 2. Ganglion and neural gland of Botryllus Gouldii, seen from the right side. 



Reference letters. 

 A anterior; a atrial opening; at atrium; be blood corpuscles; cf ciliated funnel; 

 CO body cavity; D dorsal; ec ectoderm; en endoderm (pharyngeal surface of gill); g gill 

 (in which the large, central blood-space is shown) ; gg ganglion ; gl gland ; gl' anterior, 

 enlarged chamber of gland ; gl" posterior, thick-walled portion of gland ; L left ; m mouth ; 

 P posterior; ph pharynx wall; .ß right; V ventral. 



