THE HYPOPHYSIS IN REPTILES 261 



stance is frequently found in the lumina. Such tubules, having 

 the appearance of ducts, are never found in the pars tuberalis 

 proper. A definite connective tissue sheath separates the an- 

 terior end of these bands from the anterior lobe, but it dis- 

 appears caudally, the bands blending into the ventral part of 

 the anterior lobe and with it becoming enclosed in a dense 

 fibrous tissue. 



Irregular cords, with a more or less prominent border of cyto- 

 plasm, form the main part of the anterior lobe. The cells are 

 polyhedral and stain irregularly, some taking eosin readily while 

 others in the same section of a cord are almost as clear as those 

 derived from the lateral lobes. In the clear cells a reticular 

 network is present. With iron haematoxylin and orange G. 

 some cells have a bluish-black granulation, others are yellowish- 

 brown and finely granular, while a third kind are clear, showing 

 a yellowish-tinted reticulum (fig. 59). Near the border, par- 

 ticularly near the ventral side, the darker staining cells are less 

 numerous. There are three or more rows of round nuclei, flat- 

 tened or irregularly indented, in the center of the columns. They 

 have a definite membrane, distinct but fine chromatin network, 

 and one or several prominent nucleoli. In the clear, lightly- 

 staining cells, the nuclei are near the center of the cell, while in 

 the other cells the position is eccentric, frequently lying toward 

 the center of the cord. 



In the alligators received earlier in the fall no secretory masses 

 were found in the pars intermedia, and the occasional, deeply- 

 staining peripheral borders are less prominent. The cells of the 

 pars tuberalis are small and irregular, and there are only a few 

 clear cells in the anterior lobe. However, some cells of the 

 anterior lobe stain bluish and others a deep pink with haema- 

 toxylin and eosin. In the large alligator, the many clear non- 

 granular cells of the anterior lobe and the densely-staining cells 

 of the pars intermedia and anterior lobe may be due to the 

 activity of the animal before being killed. Cushing and Goetsch's 

 ('15) study of the hypophysis of the opossum during hiber- 

 nation suggests that the smaller alligators may have been in a 

 similar state. 



