1906.] OF MONKEYS IN THE MENAGERIE. 565 



that it is considerable in normal cases, and Dr. Steegmann's 

 observations prove that the actual birth may be accomplished 

 in not more than fifteen minutes. Both the suflering and the 

 duration of the birth in the Pigtail must be attributed, I think, 

 at all events in part, to its being a case of foot-presentation, 

 which I assume, from the analogy supplied by other animals, to be 

 abnormal *. Abnormality was further attested, as I afterwards 

 learnt, by the leaving of the placenta by the mother, for Dr. Steeg- 

 mann's evidence on this point was fully confirmed by the behaviour 

 of the female Rhesus, who was actually seen by the keeper, Hefier, 

 to devour the placenta entire. 



Devouring the placenta by the mother seems to be the invariable 

 rule in all species of Mammalia, with the exception of Man t. 

 The habit has no relation to the natural food of the species, being 

 common to purely herbivorous ruminants, to herbivorous or 

 omnivorous rodents, to Monkeys, and to Carnivora. The catho- 

 licity of the habit suggests that it must have some significance 

 from the point of view of utility to the species practising it. In 

 the case of animals like Rabbits, Rats, and Carnivora, where the 

 mothers lie up Avith helpless young, a certain measure of utility 

 may lie in the necessity for keeping the spot clean and sweet- 

 smelling. 



That this is not a complete explanation, however, is suggested 

 by the reflection that in the case of Dngulata the young are active 

 and soon after birth wander away with the mother. The same 

 argument applies to Monkeys, where the young are born in trees 

 and are carried away by the mother directly afterwards. Again, 

 some animals, as is shown by the female N. -American "Wolf 

 [Canis occidentalis), now in the Zoological Gardens, stay for a 

 couple of days with their young without feeding. In instances of 

 this kind it is conceivable that the eating of the placentte has a 

 nutritive as well as a hygienic significance. But this view of the 

 matter does not meet the case of Antelopes and their allies, which 

 will start grazing as soon as the young is born. That the habit 

 has some deeper meaning than those discussed above seems there- 

 fore to be pi'obable. Perhaps, as has been suggested to me by 

 Dr. J. Rose Bradford, the hastening of milk-secretion is its 

 underlying physiological cause. In this hypothesis may possibly 

 be found the explanation of the delay that commonly occurs in 

 the human female betv/een parturition and lactation, since prac- 

 tical synchronism between the two phenomena is met with in 

 placentivorous mammals. 



The amount of haemorrhage that took place after birth diflfered 

 greatly in the Japanese and Rhesus Macaques. In the Rhesus 

 scarcely any was noticed, but in the Japanese it continued for 

 two daj's and was quite considerable in quantity. 



* Dr. F. G. Parsons, F.Z.S., suggested at the Meeting when this paper was read 

 that the length of time occupied by the birth might have been due to the young 

 being the tirst to which the mother had given birth. 



f I have been unable to discover if the instinct has been retained by any savages. 



