DISTRIBUTION OF SUBCUTANEOUS VESSELS IN GANOIDS 8^ 



found blood in these spaces is accounted for by Vialleton as 

 being an entirely abnormal condition, which is brought about 

 by a hemorrhage of the delicate branchial vessels into these 

 cavities, as a result of excitement from capture. As to consid- 

 ering these spaces lymphatic cavities, Vialleton points out that 

 they differ widely from other cavities designated by that name, 

 and throws out a strong warning about the abuse of that term. 

 Since the peri-branchial spaces are only developed in Petro- 

 myzon after metamorphosis, Vialleton pronounces these cavities 

 to be a special apparatus adapted to the movements of the re- 

 spiratory sacs. Neuviile {of. cii., p. 54), in opposition to the 

 general opinion, holds that no separate chylous system is to be 

 found in the digestive tract of the Cyclostomes. As a study in 

 comparative anatomy I injected the blood vessels of the Pacific 

 Bdellostoma (= Polistoti-cma) and found that the intercostal 

 arteries alternated with the intercostal veins in supplying the 

 septa between two myotomes, there being but one blood vessel 

 for each septum, but for each septum there is an additional inter- 

 costal vessel that terminates in an abdominal sinus, which runs 

 parallel with the aorta. This system we take to be lymphatic 

 rather than a separate venous system. No attempt was made 

 to determine how the injecting mass reached this system ; 

 whether it passed through venous-lymphatic openings or 

 whether it broke through the delicate walls of the blood- 

 vessels. 



Robin (23, pp. 22-30) gives an excellent account of the early 

 work of Monro and Fohmann on the lymphatics of the Sela- 

 chians. The former, it seems (14), described the chylous ves- 

 sels of the viscera fairly well, except that he portrayed the 

 common visceral reservoir as continuing along the vena cava 

 (cardinal) in order to empty into the sinus of Monro (precava or 

 ductus Cuvieri) ; while according to Robin (p. 2) there are two 

 triangular reservoirs, corresponding in position to the two car- 

 dinal sinuses, into which they are discharged. Lymphatics are 

 indicated as coming from the pectoral fin, brain, eye, and ear, 

 and the veine jugulaire anterieure (inferior jugular) is regarded 

 as a lymphatic trunk. Monro confused the lateral line canal 

 for a lymphatic trunk, and because he saw the injecting mass 



