DEVELOPMENT OF SUPRAPERICARDIAL BODY 



387 



and receives a sheath from its fascia. The form of the gland 

 at this time is very similar to that of the 'pup.' The pharyngeal 

 diverticulum, located at about the middle of the gland, is solid 

 and is much shorter than that of the 'pup.' The whole gland at 



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Fig. ? Transverse section through the pharynx of a 95 mm. embryo (H. E. 

 C. 1882) at the level of the supraperieardial bodies. X 24. Nch., notochord; 

 Ph., pharynx; M.cb., musculus coracobranchialis; C.c, ceratobranchial carti- 

 lage; P., pericardium; Cb.c, cardiobranchial cartilage; A., artery; V.i.j., in- 

 ferior jugular vein; R.s.b.-L.s.b., right and left supraperieardial bodies; VI, is 

 placed in the ventral diverticula of the sixth gill-pouches; At., atrium; P.c, 

 pericardial cavity; Vt., ventricle. 



this stage appears to be the result of repeated budding and 

 branching of the tubules of the earlier stages. The greatest 

 proliferation has occurred in its caudal half between the connect- 

 ing-stalk and the large tubules which represent the termination 

 of the ventral vesicle. 



