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•E. A. BAUMGARTNER 



median line. The second shows a slit-like lumen in the anterior 

 lobe, and the pars intermedia attached to the floor of the brain 

 near the infundibulum (fig. 40). The entire anterior lobe lies 

 somewhat to the left of the mid-sagittal line of the brain. 



Heterodon platyrhinos, 40 to 70 cm. in length, and Eutaenia 

 sirtalis were used for the study of the adult snake hypophysis. 

 In a median sagittal section of the latter (fig. 46) the infun- 

 dibulum is closely surrounded by a relatively thick pars intermedia, 

 which in turn is partially encircled by the anterior lobe. The 



Figs. 39 to 41 Transverse sections of the hypophysis and brain floor of a 12 

 cm. (total length) Eutaenia sirtalis embryo. X 40 (W. U. C. 48). Fine stipple, 

 anterior lobe; lined, pars intermedia; black, brain and infundibulum. v, vein. 



Figs. 42 to 44 Transverse sections of the hypophysis of an adult adder 

 (Heterodon platyrhinos). X 20 (W. U. C. 194). b, basis cranii; C, carotid 

 artery; stipples and lines as in figure 39. 



latter is a rather thin elongated mass with a small rounded an- 

 terior end. The dorsal surface of the anterior lobe lies against 

 the floor of the brain for a short distance. Between the two, 

 at the anterior end, a thin layer of connective tissue is interposed. 

 In a sagittal section to the right of the median line, the anterior 

 lobe is thicker than in the section just described. 



A series of transverse sections of Heterodon show that in this 

 form, as in Eutaenia, the anterior lobe lies to the right of the 

 median line. The first section (fig. 42) of the series shows a wide 

 anterior lobe, the left side of which is near the brain floor. The 



