78 HAYATO ARAI 



and a half to two times more than the control ovary. This 

 indicates that changes in the total nmnber of ova do not cause 

 the hypertrophy of the surviving ovary. 



4. The hypertrophy of the surviving ovary is produced by a 

 greater abundance of well-developed normal and degenerate 

 follicles, as well as by an excess of corpora lutea. This indicates 

 an increased activity of the surviving ovary due to some unknown 

 stimulus. Changes in the ovarian stroma influence but shghtly, 

 if at all, these results. 



5. Semispayed females produce litters containing nearly as 

 many young as those from the control rats. 



6. The time of the first ovulation in the sm-viving ovary is 

 identical with that in the normal ovary. Both occur at like 

 phases of body development. 



7. The young female albino rats separated from the males 

 show a slightly slower growth and maturing of the ovary than 

 do the females kept with the males. 



8. The retardation of body growth in the female albino rats 

 coincides with the appearance of the mature normal and degener- 

 ated large follicles, while after the complete removal of these 

 folUcles — double spaying — the growth rate is more rapid than 

 in the intact animal. 



