12 Paraphysis and the Pineal Region in Necturus Maculatus 
though the epiphysis is a little larger it has been displaced considerably 
caudad, as this part of these sections was unluckily somewhat injured. 
_Fia. 17. Brain of adult necturus. 
Sagittal Section, * 88 diams. 
Fig. 17 is a section through the 
brain of an adult necturus. This 
drawing is magnified 38 diams. only, 
as it was too large to draw on the 
same scale as the preceding figures. 
The paraphysis, P, forms a very 
complex structure extending far for- 
ward above and between the hemis- 
pheres. It consists in a general way 
of a proximal and a distal part. The 
former is broad and thick, and ex- 
tends forward and upward. It then 
turns forward at quite a marked 
angle to form the distal part, which 
is narrow and.tapering. The central 
canal in the proximal part is very 
large and irregular, but in the distal! 
portion much narrower. From all 
parts of this canal a large number of 
tubules are given off, which extend 
in every direction, and _ between 
which lies a confused mass of blood- 
vessels. One sees here a large vessel 
ventrad to the organ, and a smaller 
dorsad to it, the same relations as 
appear at 12.4 mm., Fig. 6. From 
these vessels branches pass into the 
choroid plexuses. 
Fig. 18 is a transverse, section of 
an adult brain corresponding ap- 
proximately to the line A-B, Fig. 17. 
This is drawn on the same scale as 
most of the preceding figures, 63 
diams. The paraphysis, P, is seen in 
the median lne between the hemi- 
spheres. It shows a distinct central 
cavity, with many tubules running out in every direction, between which 
is a mass of blood-vessels of all sizes. Below a portion of the telen- 
cephalic plexus and the plexus of the hemispheres are seen. 
