John Warren 19 
of meeting point for the-veins of the fore and mid brains. He shows 
beautifully in his injections how veins pass both dorsad and ventrad to 
the paraphysis to enter the plexuses, and how closely these vessels are 
related to the tubules of this structure. Mrs. Gage shows practically the 
same arrangement in Diemyctylus 
As regards the arteries Schobel shows that they are much smaller than 
the veins, and describes a small vessel passing caudad to the hemisplieres 
to pass eventually into the plexuses. The intercrescence of the tubules 
of the adult paraphysis and the veins is shown clearly in Fig. 20, each 
vessel and tubule lying back to back with no connective tissue between 
them. In view of all these facts it seems evident that the circulation of 
the paraphysis is sinusoidal. According to the above descriptions, the 
development of the paraphysis into a complicated, glandular organ, which 
is also very vascular, seems to be a striking characteristic of the amphibia. 
In lacertilia the paraphysis of Anguis fragilis has been studied by 
Francotte and of Lacerta vivipara by Francotte (10, 11, 12) and 
Burckhardt (3). The latter shows the paraphysis in an embryo of 
13 mm. as a narrow tube with a slightly expanded distal extremity, 
much as that of Necturus of 15 mm. Francotte describes the paraphysis 
of Lacerta vivipara as a long tube giving off a mass of tubules which 
les under the parietal eye, and resembles the epiphysis of birds (11, Fig. 
14; 12, Fig. 24). In Anguis (10, Figs. 15 and 19) the paraphysis forms 
a long narrow sack, with somewhat convoluted walls, which curves back 
over the post-velar arch to end in close relation to the parietal eye. 
The conditions in the lizard are essentially the same (10, Fig. 31). 
In Phrynosoma coronata Sorensen (35, Fig. 2) describes the paraphysis 
as a long, narrow tube, immediately cephalad to the epiphysis. 
In the ophidia Leydig (26, Fig. 6) shows the paraphysis of an embryo 
of Vivipara urcini near birth as a large, wide tube with no convolutions 
or diverticul and practically the same conditons in a young “ Ringel- 
natter ” and Tropidonatus natrix (26, Figs. 5 and 2). 
Among the chelonia Voelzkow (39) has described the paraphysis in 
Chelone imbricata as at first a wide tube much convoluted, which later 
decreases somewhat in size. (Figs. 21 and 22.) Its distal end inclines 
caudad close to the epiphysis. In Chelone mydas Humphrey (20, Fig. 7, 
Pl. IL) shows the paraphysis as a long tubular structure, giving off small 
tubules, and in an embryo of Chelydra it appears as a large, wide sack, 
from which tubules arise. It is in closer relation to the epiphysis than 
in Chelone mydas or imbricata. 
In Cistudo Herrick shows a model of Sorensen (15, Fig. 5, Pl. VI) 
of the paraphysis, which is a wide tube with convoluted walls and tubules. 
