90 ALLEN 



In the beginning of his paper he gives a most complete historical 

 sketch of all the work done on the circulatory and lymphatic 

 systems of fishes, and contends that all the vessels found in the 

 digestive tracts of the Cyclostomes and Selachians are either 

 arteries or veins and that a separate chylous system does not 

 exist. He, however, finds a double venous system on the diges- 

 tive tract of Acanthias vulgaris; one of which is the portal sys- 

 tem, and the other system, which is figured on p. 92, he 

 recognizes as corresponding to the descriptions of the chylous 

 system as given by Robin and the older authors. Nevertheless 

 he considers them as veins for the following reasons : First, on 

 p. 90, he has found the sinus 5/0fl/<2tf / (Cisterne de Pecquet of 

 Fohmann) to be full of blood. Second, on p. 94, he finds that 

 upon injecting this system that the entire portal system is im- 

 mediately filled. According to Neuville the system of absorp- 

 tion is entirely carried on by the veins in these groups, and with 

 the Cyclostomes he finds the arrangement of the veins less com- 

 plex than in the Selachians, which is in accord with their less 

 complicated digestive tract. 



A year later Vialleton (op. ctt.} takes up the same problem 

 from the standpoint of the digestive tract of Torpedo, and 

 claims that Neuville was too hasty in his conclusions. In reply 

 to the two objections raised by Neuville as to this system of 

 vessels being veins rather than chylous, Vialleton says (p. 382) 

 in answer to the first that it is not strange to find blood in a 

 lymphatic trunk. As regards the second he states (p. 383) that 

 Neuville much less than Mayer has not attempted a micro- 

 scopical study of these vessels, that since he has not seen the 

 connections of the superficial canals with the veins he does not 

 know but that they may be only artifacts, and further declares that 

 a histological investigation revealed the fact that these communi- 

 cations were found to be caused by the rupture of the venous 

 wall, which is a contact wall between these two systems. Vial- 

 leton found (pp. 452-3) that there were distinct superficial and 

 profundus lymphatic networks in the digestive tract of Torpedo, 

 which could readily be told from the venous capillaries on 

 account of the form of its network, its regular caliber, and 

 greater volume. By injecting the lymphatics of the intestine 



