138 NEW YORK ZOOLOGICAL SOCIETY. 



in our work, in the hope that concerted study may render the 

 prevention and treatment i>f the ihsease more clear and ultimately 

 successful. 



OCCUKKKNCE. 



The occurrence of this disease is udI restricted to animals from 

 any particular geographical area, or to any special season of the 

 year, having come under nur observation in each of the four 

 seasons. 



Species .Wlcctcd. — The disease among wild aninuds occurs in 

 sapajous, macaques, Diana monkeys, green inonkexs and baboons, 

 in point of fre(|uencv in the order named. 



Age. — The disease ma\ affect either voung or old animals. 

 While there seems to be no marked relation between age and 

 occurrence, it more frequently manifests itself in those animals 

 which have been in captivity for some time, ralluT than in those 

 recentlv arrived. 



Sex. — The disease occurs in ])olh ^i'M's. The greater ])ropor- 

 tion under our observation have been males. This is exactly 

 contrary to the condition in man. where osteomalacia occurs 

 almost exclusively in females, and is most commonly seen bear- 

 ing a close relationship to the puerperal state. It is therefore 

 interesting that in the species most closelv allied to man, it occiu's 

 without this relationship, and in ;inimals in which ])rocreation 

 during ca])tivit\' is exceptional. 



While continemcnl has a manifc-st intluence, we are still in the 

 dark concerning the essential etiological factors in the causation 

 of this affection. 



A deficiency of eartlu' salts in the food wduld seem to be a 

 natural explanation. The ]iresence of an infecticjn has been sug- 

 gested, but if this exists, it must be habittially introduced in the 

 fofjfl or water, rather than transmitted from animal to animal. 

 Healthy animals have been associated with those diseased for 

 an indefinite length of time, without apparent injury, and com- 

 parison to a similar condition in man, would seem to exclude this 

 jjossibijity. A morbid pecidiarity of the constitution, and a spe- 

 cial preflisposition seems to be requisite for the causation. When 

 this suscejitibility to the disease exists, tlun exposure in ill-venti- 

 lated, small and dark cages probably acts as an exciting cause. 



