138 NEW YORK ZOOLOGICAL SOCIETY: 
in our work, in the hope that concerted study may render the 
prevention and treatment of the disease more clear and ultimately 
successful. 
OCCURRENCE. 
The occurrence of this disease is not restricted to animals from 
any particular geographical area, or to any special season of the 
year, having come under our observation in each of the four 
seasons. 
Species Affected—The disease among wild animals occurs in 
sapajous, macaques, Diana monkeys, green monkeys and baboons, 
in point of frequency in the order named. 
Age.—The disease may affect either young 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, rather than in those 
recently arrived. 
Sev.—The disease occurs in both sexes. The greater propor- 
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 closely allied to man, it occurs 
without this relationship, and in animals in which procreation 
during captivity is exceptional. 
ETIOLOGY. 
While confinement has a manifest influence, we are still in the 
dark concerning the essential etiological factors in the causation 
of this affection. 
A deficiency of earthy salts in the food would seem to be a 
natural explanation. The presence of an infection has been sug- 
gested, but if this exists, it must be habitually introduced in the 
food 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 
possibility. A morbid peculiarity of the constitution, and a spe- 
cial predisposition seems to be requisite for the causation. When 
this susceptibility to the disease exists, then exposure in ill-venti- 
lated, small and dark cages probably acts as an exciting cause. 
