386 



WALTER E. CAMP 



the epithelial wall of the pharynx. The ventral portion of the 

 gland, especially in its cranial half, is formed of a large dilated 

 vesicle, broken up in its caudal portion into several smaller 

 vesicles and tubules. The large mass of tubules between the 

 connecting-stalk and the ventral vesicle is very irregular and com- 

 plicated. Some of the tubules are completely isolated, but many 



Fig. 6 Ventral view of a wax reconstruction of the caudal half of the pharynx 

 of an embryo 95 mm. long (H. E. C. 1882). X 12. Ph., pharynx; IV to VI, 

 fourth to sixth gill-pouches: Th., thymus; D.o., dorsal outpouching; V.o., ven- 

 tral outpouching; R.s.b.-L.s.b., right and left suprapericardial bodies; Oes., 

 oesophagus. 



of them are fused over small areas of their walls, but contain 

 independent lumina. Apparently true anastomoses are found 

 in a few places. 



Figure 28 shows the tubules of the gland of a newborn fish 

 (23.5 cm. long) which was cleared in oil containing enough stain 

 to bring out the gland tubules and blood vessels distinctly. The 

 caudal half of the gland rests upon the coracobranchial muscle 



