332 MICHAEL F. GTJYER 



change in oxyphile cells, in males there was a noticeable increase in the 

 numbers of this type of cell as well as of basophiles. 



While it seems not improbable that what exists in the females injected 

 with nucleoprotein is essentially a castrate condition, the ovary being 

 functionally so affected as to be incapacitated, this conclusion cannot go 

 unchallenged, since it may be possible that the injected material acted 

 simultaneously on ovary and pituitary. In an earlier study (Guyer and 

 Claus, 1932) it was found that transplanted cancer, after about two months 

 of growth, induced much the same histological picture in the anterior pitui- 

 tary lobes of both males and females as that following castration, yet in the 

 case of cancer the action seemed to be directly upon the pituitary, since no 

 visible ovarian modifications could be detected, and the females continued 

 their oestrous cycles and even bore young up until they were practically 

 moribund. 



In order to test their relative potencies in bringing about precocious 

 sexual development, the anterior pituitary lobes of nucleoprotein injected 

 rats and of controls were transplanted into immature young rats and mice 

 so selected as to correspond in age. It was found that in general a greater 

 development of the ovaries of the young animals followed implantation of 

 anterior pituitaries from nucleoprotein-treated rats, than corresponding 

 implants from normal rats, indicating increased potency of the former. The 

 anterior pituitary lobes of castrate rats are also known to be more potent 

 in this respect than are the lobes of non-castrates. 



