436 E. A. BAUMGARTNER 
Fig. 36 Sagittal section of the superior end of the hypophysis of a 21 mm. 
embryo. (H.E.C. 1493). x 450. 
Fig. 37 Sagittal section of the superior lobe of a 50 mm. embryo. (H.I.C. 
Series 444). x 450. 
is an outer cytoplasmic zone which is non-granular and stains 
lightly. The nuclei are smaller than in the 21 mm. embryo and 
contain less chromatin. As Sterzi has stated, there are some 
spherical nuclei and some more slender oval nuclei, but no regular 
arrangement of these, such as Sterzi described, was observed. 
In a 95 mm. embryo, the roof of the superior lobe has increased 
in thickness (fig. 38). The nuclei are oval and contain a denser 
network of chromatin than is found in 50 mm. embryos. Along 
the periphery many of the nuclei are spherical. There is an 
inner zone of cytoplasm as in the 50 and 21 mm. stages, which is 
