Lymphatics and Enteric Epithelium of Amia Calva 369 



111 contradistinction to the statements of the authors above 

 mentioned, Robin says " I have satisfied myself by numerous 

 observations and experiments, that the cutaneous and sub- 

 cutaneous vessels described by Monro, Hewson, Hyrtl, etc., 

 as lymphatics, are veins The division of the lym- 

 phatics of fishes into superficial and deep or visceral, still 

 adopted by some modern authors, must consequently be aban- 

 doned. The first of these classes of vessels does not exist in 

 this class of vertebrates." As the conclusion to his article 

 Robin turther says, "the general result of these researches has 

 been to demonstrate that the subcutaneous vessels which I 

 have described in the selachians as being lym- 

 phatics, are veins and not lymphatics at all. This conclusion 

 is found entirely confirmed by the descriptions contained in 

 this memoir ; they prove, indeed, that fishes have no other 

 lymphatics than the chylous vessels, and those of the peri- 

 toneum lining the genito-urinary organs and the pericardium." 



So far as I have been able to ascertain, no other writer 

 shares this opinion. Indeed from the statements of various 

 authors and from my own observations, I think Robin was 

 wrong in calling the subcutaneous vessels, veins rather than 

 lymphatics. In a specimen killed by pithing, the cephalic 

 lymph sinus was exposed while the heart was still beating ; 

 the veins were gorged with blood but the lymph sinus ap- 

 peared perfectly clear and transparent, and at no time was 

 blood found in the lateral vessels. In several instances a 

 clear fluid was seen to run out of the lateral vessel, when cut, 

 in a fresh specimen. 



The arrangement of the lymphatic veselsof ..4;;//a calva has 

 been found to agree, in general, with that of various other 

 fishes, as described by the several authors, but in some re- 

 spects there is a marked difference. The system consists of 

 the two parts, a peripheral or subcutaneous and an ental or 

 visceral portion. 



To satisfactorily demonstrate these vessels they may be in- 

 jected but the precaution must be taken to first inject the 

 veins, otherwise the two sets of vessels can not be distin- 

 guished with certainty. A convenient place for injecting the 



