464 CHARLES R. STOCKARD AND E. M. VICARI 



1 shows a longitudinal section very near the sagittal plane 

 of the pituitary from 1523 $ . The details of this photomicro- 

 graph resemble with fair constancy the same sections from 

 the dachshund pituitaries shown in plate 87. The anterior 

 pituitary is long and thin and completely surrounds the pars 

 nervosa, being fused with it at the distal end through the 

 pars intermedia. Also at the distal end of the gland the pars 

 intermedia evaginates toward the nervosa, penetrating it 

 and carrying in a portion of the residual lumen. A cleft lined 

 by a thin layer of intermedia cells is thus formed in the 

 posterior region of the pars nervosa. This, as shown in plate 

 87, is commonly seen in the dachshund pituitaries. 



The pars nervosa in this pituitary is normal in appearance 

 and not deeply invaded by intermedia cells. The pars inter- 

 media is thin, and extends completely around the nervosa and 

 partly onto the infundibular stalk, which is also a feature 

 common in the dachshund. The intermedia contains numerous 

 colloidal follicles throughout its extent. 



The pars distalis of this F 2 pituitary completely surrounds 

 the nervosa dorsally as well as ventrally, and like most dachs- 

 hund pituitaries thus violates Tilney's apt likening of the 

 relation of posterior to anterior pituitary in the dog to that 

 of a ball lying in the depression of the catcher's glove. The 

 "ball" in this case is completely encased, a condition which 

 has not been observed in the Boston terrier or the bulldog 

 glands. In removing the pituitary from the bulldog breeds 

 at autopsy, one must exert care so as to avoid having the 

 nervosa fall away from the pars anterior. 



In our experience, the general form of the anterior pituitary 

 in the dachshund inclines toward long and thin, permitting 

 the nervosa to become encased within it. In the Boston terrier, 

 however, the pars anterior is thicker and shorter and the 

 nervosa is covered by only the thinnest layer of intermedia 

 over its dorsal surface. 



The cells of the pars distalis in 1523 $ are rather closely 

 packed and with few spaces except in the ventro-peripheral 

 zone; there is a slight tendency toward cord-like arrange- 



