179 



reference to the work of Feancotte, that the eye-capsule in Anguis 

 (the very animal upon which Beraneck made his observations) is, at 

 an earlier period than Beraneck describes, actually connected with 

 the epiphysis, and that it, apparently, is an outgrowth from the latter. 

 From his own researches, he shows a similar relationship between the 

 two vesicles in Iguana. Strahl and Martin, Beraneck and others 

 have shown the same early connection between the two vesicles in 

 Lacerta and Anguis. 



While I recognize the correctness of these observations ; neverthe- 

 less I think it is an open question, whether the vesicles do not in 

 some animals arise independently and become subsequently crowded 

 together. I is very desirable to have views representing even earlier 

 conditions than those figured by de Klinckowström. I am indebted 

 to Mr. Hill's 1 ) forthcoming contribution for this suggestion. Hill 2 ) 

 has already shown in a published article the presence, in Coregonus 

 albus, of two vesicles of independent origin; more recently he has 

 studied these two epiphysial outgrowths in living embryos of Salmo, 

 Catostomus, Lepomis, Stizotedion and in sections of Amia and the 

 other genera mentioned. He shows that the two vesicles open by a 

 common passage into the third ventricle and that they are associated 

 in a manner altogether similar to those in de Klinckowström's figs. 

 From their earlier condition, he concludes "that the vesicles arise 

 separately and that as they grow in a dorsal direction, they carry a 

 part of the brain-wall with them and thus form a common median 

 passage". "The only reason (says Hill) for regarding the anterior 

 vesicle as formed at the expense of the distal end of the posterior 

 vesicle is that it is smaller, and, aside from this single fact, one might 

 with equal force consider the posterior vesicle as formed at the ex- 

 pense of the anterior." I cannot, of course, do justice to Mr. Hill's 

 position here, and I refer to it in advance, only on account of its 

 direct bearing upon the question in hand, and because the memoir is 

 already completed and is on the way to publication. 



The question of the independence of the epiphysis requires further 

 elucidation. 



The observations I have recorded above afford the suggestion that 

 the epiphysis, if present as an independent structure, was primitively 

 visual in character. It will be in harmony with these observations 

 to account for two distinct structures, when they occur, by reference 



1) Through, the courtesy of Professor Reighabd, in whose laboratory 

 the work was done, I have been permitted to read in the manuscript 

 the article of Mr. Charles Hill on "The Epiphysis of Teleosts and Amia". 



2) Journ. Morph., Vol. V, No. 3, p. 503. 



