THE " SEXUAL SEASON OF MAMMyVLR. 47 



the above^ blood may be added for a large number of animals, 

 some of which rarely, some frequently, and some always 

 suffer from a loss of blood. While, finally, more or less com- 

 pact masses of uterine stroma tissue are included in the 

 discharge of the Primates and some of the lower mammals. 

 Blood has been observed in the discharge during pro-cestrum 

 in the mare, ass, cow, sheep, goat, pig, cat, rabbit (Aristotle ; 

 Ellenberger, 1892; Fleming, 1878; Wiltshire, 1883), and rat 

 (Lataste, 1887) ; it is also recorded as having been observed 

 in marsupials (Wiltshire, 1883); in the bitch it is almost 

 invariably present, and so also it would appear to be in 

 Pachyuromys duprasi, Dipodillus simoni, Meriones 

 shawi (Lataste, 1887), and in Tnpaja javanica and 

 Tarsius spectrum (Stratz, 1898). Inmostof these animals 

 there is only enough blood to tinge the discharge more or 

 less, but in the bitch, and probably T. javanica and T. 

 spectrum, there is a flow of blood almost as concentrated 

 as that recorded for monkeys (Heape, 1894, 1897). 



It has been recorded for a large herd of highly bred 

 Alderney or Jersey cattle in the south of England, that a 

 discharge of blood is of regular recurrence among' them 

 (Wiltshire, 1883) ; but so far as I can learn this is excep- 

 tional, although its occurrence in individuals is by no means 

 rare. It has been suggested that bleeding in the lower 

 mammals during pro-CEstrum is confined to domesticated 

 species, but this is not true (Lataste, 1887; Stratz, 1898; 

 Wiltshire, 1883) ; at the same time it is not improbable that 

 the circumstances attending domestication tend to increase 

 the flow of blood from the uterus, and that highly bred 

 domesticated animals are more liable to experience it than 

 those which are hardier, less carefully attended to, and less 

 luxuriously fed. 



The pro-oestrous discharge, then, varies in quality in dif- 

 ferent animals, and not only is this true, but it varies at 

 different times in the same animal, both as to quantity and 

 quality. There is ample evidence of this in various human 

 tribes (Holder, 1892, Ellis) and in individuals. Among 



