330 THE PHYSIOLOGY OF REPRODUCTION 



recurrence of prooestrum and oestrus. Moreover, Sherrington,^ 

 after transecting the spinal cord of a bitch in the cervical region, 

 and headwards of the connection between the sympathetic 

 system and the cord, observed that heat of normal duration 

 and character continued to recur in the animal so operated 

 upon. The case, described by Brachet,^ of a woman suffering 

 from paraplegia in the lower part of the body and legs, but who 

 conceived and became pregnant, may also be cited. 



There are other facts which indicate that menstruation is 

 not caused by a nervous reflex set up by ovulation or by the 

 pressure of the growing foUicles. Gjniaecologists have pointed 

 out that in the human subject ovulation and menstruation are 

 not necessarily associated, and Heape ^ has shown that the 

 ovaries of menstruating monkeys do not always contain follicles 

 in a state approaching ripeness. 



But whereas the evidence is clear that heat and menstruation 

 are not brought about by nervous reflexes arising from the 

 ovary, it is equally obvious that these processes are dependent 

 upon some ovarian influence. For, if the ovaries are removed, 

 heat and menstruation no longer take place. 



Some authors, however, have denied this, and cases have 

 been cited of the occurrence of menstruation after surgical 

 ovariotomy. For example, three cases have recently been 

 described by Doran,* in each of which the two ovaries were 

 beheved to have been removed, although menstruation recurred 

 at irregular intervals after the operation. Further cases have 

 lately been reported by Blair Bell ^ and other writers. It seems 

 probable that these exceptional cases are to be explained on 

 the supposition that the extirpation of ovarian substance was not 

 quite complete, and that the tissue which remained behind 

 underwent hypertrophy subsequently to the operation. That 



"^ Sherrington, The Integrative Action of the Nervous System, London, 

 1906. 



' Brachet, Recherchea, 2nd Edition, Paris, 1837. 



' Heape, " The Menstruation and Ovulation of Macacus rhesus," Phil. 

 Trans. B., vol. clxxxviii., 1897. 



4 Doran, " Sub- total Hysterectomy for Fibroids," Lancet, Part II., 

 November, 1905. 



* Blair Bell, " Preliminary Note on a New Theory of Female Generative 

 Activity," Liverpool Medico-Chirurgical Journal, July 1906. 



