14 Paraphysis and the Pineal Region in Necturus Maculatus 
Fig. 19 is from a wax reconstruction of the adult paraphysis on a 
scale of 120 diams., made from the same series as Fig. 18. The angle 
between the proximal and distal parts is quite striking, and is much more 
marked in Ichthyophis (Burckhardt, 4, Fig. 1), but of course this division 
into proximal and distal parts is really a purely arbitrary one. This 
model gives a good idea of the complex structure of the organ. The 
tubules are of all shapes and sizes, often convoluted and anastomosing 
with each other. The spaces between them, which the vessels occupy, are 
quite large and striking. 
Fic. 19. Wax model of paraphysis of adult necturus, same series as Fig. 
18, X about 120 diams. 
Fig. 20 represents a small portion of the paraphysis of Fig. 17, mag- 
nified 560 diams., and shows clearly the relation of the tubules to the 
vessels. In the centre of the figure is a tubule, 7, dividing into two 
branches, 7’, T?. Surrounding these tubules on every side are sinusoids, 
st., whose flat endothelial cells are seen lying directly against the epithelial 
wall of the tubules with no connective tissue between them. We find 
here in order first a sinusoid, then a tubule; then another sinusoid and 
another tubule, and finally a sinusoid. The wall of the tubules consists 
of a single layer of cells with large oval nuclei and very indistinct cell 
boundaries. The nuclei contain masses of granules arranged very irregu- 
