190 PHYSIOLOGY OF FARM ANIMALS [CH. 



over it has been established that these developmental changes, 

 both uterine and niammaiy, do not occur in the absence of corpora 

 lutea, as Avhen ovulation had not taken place at oestrus. Experi- 

 ments have proved clearly that both the uterine growth and the 

 mammary growth are dependent upon the presence of luteal 



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/ .," ■ ' '-■• ' , . ' - '' . .'•;v'\i- '•■''^'■'-■'.yT.. • ,"-~iV":«»M»^- ■«. 



Fig. 104. Transplanted ovary ct rat, .showing coij)oia lutea, and small follicle 

 (from Marshall). 



tissue in the ovaries, and under the influence of the corpora lutea 

 the mammary glands develop to an extent sufficient to admit of 

 milk production at and after parturition or at a corresponding 

 period at the end of pseudo-pregnancy. In polyoestrous animals 



