THE PITUITARY BODY 



mare (both pregnant and non-pregnant) is high. The quahta- 

 tive eifects, which are illustrated by the reproduced figure, 

 suggest that principally follicle-stimulating hormone is pro- 

 duced by the pituitary of the stallion and of the aged mare 

 and gelding, whereas luteinizing hormone also is secreted by 

 the pituitary of the fetus, colt, young gelding, and adult preg- 



,'^ 



.j^ 



^v,4 



»o 







^35. 



Fig. 13. — -Photomicrographs illustrating the response of the ovary of the rat to 

 equal quantities of pituitary powder from glands of horses. The magnifications 

 are the same in all cases. (From Hellbaum, Anat. Rec, 63, 147-57 [i935]-) 



/, Normal mare of reproductive age. 2, Old mare. J, Fetus. ^, Stallion. 5, 

 Young gelding. 6, Old gelding. 



nant or non-pregnant mare. Those interested in a recent 

 study of the gonadotropic effects of the anterior pituitary 

 of whales (finback, Balaenoptera physalus; sperm, Physeter 

 megalocephalus) are referred to the report of Ceiling (1935). 

 Cyclic changes in the pituitary in relation to those of the 

 gonads have again been studied by several investigators. 

 Cole and Miller (1935) could detect no change in the gonado- 



[68 1 



