GENETIC TYPE AND THE ENDOCRIXES 455 



127). As an adult bitch she whelped and reared a litter of 

 five normal puppies. 



Occasional longitudinal out-foldings of the pars intermedia 

 may give indentations along the pars nervosa; this is indi- 

 cated in part in figure 4 of plate 87. No significance for such 

 peculiarities is known. Also occurring in the dog pituitary 

 is a somewhat similar phenomenon in which the pars inter- 

 media evaginates and grows into the distal end of the pars 

 nervosa, carrying with it the space of the residual lumen. 

 This also is partly illustrated in figure 4 (pi. 87), as well as 

 figures 1 and 5 of plate 89. 



Finally, figure 2 of plate 87 exhibits a most peculiar con- 

 dition in an otherwise normal pituitary. The dachshund pos- 

 sessing this gland was a normal animal, as indicated by the 

 fact that she was an unusually good matron bitch. At the 

 distal end and in a dorsal position in this photomicrograph 

 is a considerable formation of irregularly twisted plates of 

 hyaline cartilage, in the folds of which lie perfectly developed 

 red bone marrow. All types of developing blood cells are 

 seen in the marrow, and many huge multinuclear giant cells 

 or megakaryocytes are present. Such a marrow region is 

 shown in the upper left corner of the photomicrograph. There 

 was no calcification or truly bony structure present, as proof 

 of which is the fact that the specimen cut smoothly on the 

 microtome and there was no histological evidence of bone 

 formation. The formation of cartilage and red bone marrow 

 is in direct cellular continuation with the posterior tip of 

 the pars distalis at its junction with the pars intermedia, 

 the more extensive connection being with the pars intermedia. 

 Although about 500 dog pituitaries were examined, such his- 

 tologic formation in association with the pituitary was ob- 

 served in this one case only. 



The cellular nature of the glandular pituitary in this speci- 

 men is somewhat atypical. There is an excessive amount of 

 connective tissue, and the basophiles show irregularities in 

 granular reaction, some being completely filled with deeply 

 staining coarse granules and others incompletely filled with 



