DEVELOPMENT OF THE HYPOPHYSIS 433 
Fig. 33 Sagittal section of the floor of the anterior end and of one of the tub- 
ules of the anterior lobe of a pup. X 400. 
between these are spherical shaped nuclei. He has described 
these in the roof of the superior lobe. These become more 
evident in 40 and 50 mm. embryos. In an 86 mm. embryo, the 
nuclei of the roof are to some extent irregular in arrangement. 
The cytoplasm takes orange G quite readily and hence is some- 
what acidophilic. In the pup, the floor is well formed and is 
now the thicker wall of the anterior lobe. As shown in figure 33, 
it is composed of four or five layers of nuclei. The oval nuclei 
are crowded close to the inner free surface. There is, how- 
ever, a narrow outer cytoplasmic zone which is very granular. 
The character of the cells of the glandular outgrowths is shown 
in figure 33. Here, too, there is a narrower outer rim of granular 
eytoplasm. A wider inner zone of non-granular cytoplasm 
bounds the lumina of the tubules. The nuclei, as in the floor, 
are oval. Usually two or three layers form the walls. The 
nuclei have a distinct chromatin network with occasional denser- 
staining chromatin masses resembling nucleoli. 
