40 WALTER HEAPE. 



every month ; in fact, the reverse is probably true, and the 

 excessive activity of the menstrual organ, if it is not developed 

 at the expense of the reproductive power, in many cases 

 results in lessened fertility. 



We are here doubtless in the region of pathological condi- 

 tions, since when there is a considerably increased menstrua- 

 tion, either by increase of the amount of the menstrual flow 

 or by decrease of the intra-menstrual period, it is accom- 

 panied by exhaustion and the evils which result therefrom. 



If the above be true, it would appear that civilised woman 

 has reached the limits of reproduction compatible with her 

 mode of life, and it may be concluded that increased repro- 

 ductive power will not arise until her powers of assimilation 

 are increased to a sufficient extent, and until the products of 

 that assimilation are devoted more exclusively to the repro- 

 ductive function. 



The Duration of the CEstrus in Monoestrous and 

 Polycestrous Mammals in the Absence of the 

 Male. 



There is very little known regarding this point except in 

 certain domesticated animals. The oestrus of monoestrous 

 mammals may last a short or a long time. In the Barbary 

 wild sheep in captivity (Zoo.) it only lasts a few hours. In 

 the bitch it lasts a variable time, variable both in different 

 individuals of the same species and in the same individual at 

 different times. The winter oestrus of the bitch does not last 

 so long as the summer oestrus in certain breeds ; a well-known 

 breeder (Dr. Inman) has assured me this is the case with his 

 bitches. The usual time is probably from seven to nine days. 



A most careful observei*, however, tells me that a bitch 

 which he had for many years usually remained in a condition 

 of oestrus for nine days, but sometimes it persisted in her 

 for fourteen days. Other breeders have informed me they 

 have had bitches undergoing oestrus for even a longer period 

 than this, but it is undoubtedly an exceptional experience. 



