770 



born that the parapineal organ has a nervous connection with the 

 smaller left ganglion habenulae. He also believes that the pineal 

 organ has a like connection with the right ganglion, though this he 

 has not been able to demonstrate fully. Studniöka ('93 a), p. 33 1 ). 



In Iguana, de Klinckowström describes the nerve of the pineal 

 eye as springing from a small mass of cells, the "parietal nucleus", 

 situated in front and to the right of the point of attachment of 

 the epiphysis to the brain. He states, however, that this mode of 

 attachment of the eye to the brain is secondary, for the eye is formed, 

 developmentally, by being constricted off from the distal end of the 

 epiphysis, in the same way that it is said, e. g. by Strahl and Mar- 

 tin, to originate in Anguis fragilis. 



It is well known that both Leydig and Beraneck deny that the 

 eye is formed in this way. They hold it to take origin from an 

 evagination of the brain roof in front and independent of the epiphysis. 

 This is asserted for both Lacerta and Anguis, and is particularly in- 

 sisted on by the latter author in his recent papers. 



In a paper by Francotte ('94), just received, this author alludes 

 to the fact that de Klinckowström supports his contention that the 

 eye is formed by abstriction from the distal end of the epiphysis, by 

 reference to his own (Francotte's) former paper. But the author 

 then says: "Chose extraordinaire, nous avons 6t6 induit en erreur par 

 les faits! II y a ainsi une lacune entre la phase repr6sent6e par 

 notre figure 2 et celle representee par notre figure 6 des Archives 

 de Biologie (planche XXXIX, 1888). II existe, en effet, chez Anguis, 

 comme Beraneck le suppose et comme il le d6crit chez Lacerta, 

 deux diverticules indöpendants P un de P autre et naissant de la partie 

 post6rieure de la voüte du thalamencöphale sur le plan median. Le 

 diverticule ante>ieur fournit Poeil parietal et le diverticule post6rieur 

 donne origine en partie ä la tige epiphysaire, ou epiphyse proprement 

 dite" (p. 100). 



Now it is a suggestive fact in this connection that according to 

 Leydig's account ('90) while in Lacerta agilis, e. g., there are two 

 evaginations from the brain roof, the anterior of which gives rise to 

 the eye, and the posterior to the epiphysis, they both spring from 

 "Einem Wurzelpunkte". Is it not possible that this Wurzelpunkt 



1) This author's paper ('93 b), -written in Bohemian, I am able to 

 read only imperfectly, and with the aid of a friend who likewise is not 

 entirely familiar with the language, so I am not sure what his conclusions 

 here are. His figures la and lb and 2 appear, however, to indicate an 

 independent origin of the parapineal eye. 



