330 MICHAEL F. GUYER 



twenty-five control animals injected with extract of rabbit salivary gland 

 had their fertility diminished little if at all. Although the attempt was 

 made, it was found that the sterility induced by spermatotoxins could not 

 be maintained by oral administration of dried material containing sper- 

 matozoa of the bull. 



Following the development of spermatotoxins, as just described, changes 

 in both the ovary and the anterior lobe of the pituitary body occurred. 

 Histological examination of the ovaries of such rats revealed many mature, 

 unshed ova, with evidence of lutein-like material in the walls of the follicles. 

 And sections of the pituitary anterior lobes showed an increase in oxyphile 

 cells but no visible change in basophile cells. Possibly this increase is 

 followed by the release of a secretion which induces precocious formation 

 of corpus luteum substance in the follicular wall and thus prevents shedding 

 of the mature ova. 



The oestrous cycles of sixteen rats kept sterile through injections of 

 spermatozoa were followed by means of daily vaginal smears and were 

 found to be interfered with but slightly if at all. Four of the females killed 

 within six to thirteen hours after copulation were found to have non-motile 

 spermatozoa in the vagina, uteri or oviducts. It would seem, then, that the 

 sterility induced by the development of spermatotoxins in females is due 

 more probably to immobilization of the spermatozoa in the genital tract 

 than to any interference with the oestrous cycle. However, since the 

 oxyphile cells of the pituitary anterior lobe are supposed by some investi- 

 gators to release a luteinizing substance into the blood stream, it may be 

 that in sperm-injected animals an increased amount of such material is 

 being released, which, although insufficient to suppress the oestrous rhythm 

 as manifested in the vaginal epithelium, is sufficiently potent to cause the 

 formation of corpus luteum-like material which imprisons the maturing ova 

 and prevents their discharge. 



EXPERIMENTS WITH ANTERIOR LOBE MATERIAL 



Twenty female rats were injected intraperitoneally with extract of dried 

 anterior pituitary body (0.75 cc. of a dilution of 1 part of dried material to 

 25 parts of liquid) every second or third day during a period of two months. 

 Males of tested fertility were introduced into the cages after the sixth injec- 

 tion. Of the sixteen females which survived the injections one bore three 

 young during the course of treatment, three were apparently permanently 

 sterilized, and nine displayed temporary sterility and subsequent reduced 

 fertility. The ovaries of the remaining three, killed for histological study, 

 contained more than the usual number of corpora lutea, in some of which 



