ZOOLOGICAL SOCIETY BULLETIN 



829 



HUMBOLDT'S WOOLLY MONKEY. 



appeared to sweat to a certain extent. As it 

 was necessary to carry his personal specimens 

 about during the cold winter nights, this ten- 

 dency appeared dangerous, so the sleeping box 

 of the specimens in question was experimentally 

 removed, and the animals were given a handful 

 of loose hay. This they soon cut into countless 

 fragments, gathered in a mound, while they 

 nested quite exposed within a slight concavity 

 in the center. The temperature of the room in 

 which they were kept ordinarily dropped to 50° 

 F. during the night. Moreover, the rodents 

 were frequently taken out at night, in a small 

 box within a satchel. In such cases they were 

 provided with cotton waste, but were often ex- 

 posed to very low temperatures. 



During the first six months of their captivity, 

 the writer was inclined to believe that he had 

 been particularly fortunate in maintaining this 

 lot without a single loss. At the same time, 

 fifty per cent, of the Park specimens had died, 

 though receiving every attention. The writer's 

 specimens were frequently handled, and being 

 without means of hiding had developed semi- 

 diurnal habits. With the coming spring, and 

 the loss of the remainder of the jerboas in the 

 Reptile House, the writer decided that it was 

 not mere luck that resulted in the good condi- 

 tion of his four examples against the loss of 

 ten that had been nested, with every precaution. 

 The decision was to experiment with several 

 groups of jerboas without provision for hiding. 

 About twenty examples, representing two spe- 

 cies, were obtained, and the cages provided sim- 



ply with a shallow layer of cut hay. The re- 

 sult was interesting and satisfactory. About 

 seventeen of the original twenty specimens are 

 yet in thriving condition — nearly two years after 

 beginning the test. 



The result was of considerable value, as it 

 demonstrated similar possibilities with other 

 species of secretive rodents. We have thus 

 profited in two ways. Our rodent collection is 

 not merely a series of empty cages with mys- 

 terious sleeping boxes, the contents of which 

 would be indicated by label only, but the ani- 

 mals are in view. They are surprisingly ac- 

 tive, considering the nocturnal habits of the 

 greater number of them, while an elaborate 

 series of species, some alleged to be very deli- 

 cate, is in fine condition. 



In this way we solved the problem of exhibit- 

 ing and maintaining a representative collection 

 of the smallest rodents. A number of the spe- 

 cies are quite uncommon, as regards the usual 

 run of zoological exhibits. We are now ex- 

 perimenting on the care of those species of very 

 small monkeys and lemuroids that seldom are 

 seen in captivity, owing to their extreme phy- 

 sical delicacy. We rate the marmosets, lemur- 

 oids, the pottos and the Malayan species of 

 loris, as creatures of similar feeding habits to 

 the small nocturnal species of reptiles. While 

 specimens of these species may be induced to 

 take food during the day, it is during daylight 

 that they are usually inactive, and food par- 

 taken at such times is not assimilated with the 



FLYING FOX: FRUIT BAT. 



