PARAPHYSIS AND PINEAL REGION IN REPTILIA 349 



frontal sections of paraphj'-sis, epiphysis and diencephalic plexus. 

 The same author (29) shows a Lacerta muralis similar to my fig. 

 10, and his fig. 11 of Anguis is an excellent sagittal section about 

 similar to my fig. 12. The epiphysis in this figure, however, is 

 wrapped over the head of the paraphysis lying between it and the 

 pineal eye, and the upper part of the diencephalon is not so com- 

 pressed as in my models. In fig. 23 he shows a double paraphy- 

 sal outgrowth similar to the three in the model in fig. 8. Fran- 

 cotte also gives three sections of the paraphysis in a young human 

 embryo. My results therefore are essentially similar to his. 

 The paraphysis in lacertilia develops from one, two or three 

 outgrowths and as it grows curves backward over the post velar 

 arch in the opposite direction to that in Necturus. It very early 

 comes into close relation with the veins which overlie the roof 

 of the diencephalon, but its relations to them are not so in- 

 tricate as they were in amphibia and we do not find here such a 

 perfect type of sinusoidal circulation as in Necturus. The final 

 stage, fig. 13, gives a good view of the adult condition, which I 

 have not seen elsewhere. 



In the turtle we have a paraphysis which approaches rather the 

 amphibian type. Its early stages are like those of the lizard, but 

 as it grows larger the development of lateral tubules is much more 

 marked, and therefore it has a very close relation to the veins 

 about it, so that we have here a circulation of the sinusoidal type 

 more perfect than in the lizard though not so marked as in amphi- 

 bia. In fig. 23 the paraphysis is a well marked glandular struc- 

 ture with an elaborate set of lateral tubules which, however, at 

 this stage are quite short and show no signs of anastomosing with 

 each other. For relation to vessels, see fig. 27. In the lizard the 

 tubule formation is slight except at the apex where the organ is 

 expanded and a number of tubules appear, figs. 13 and 14, which 

 show the same relations to veins as in the turtle. 



In the crocodilia Voeltzkow (96) shows a paraphysis which 

 follows closely the development in Lacerta except that at first 

 it is inclined slightly forward. In the caiman the development of 

 lateral tubules is much more marked. In Chelone imbricata the 



