564 MAMMALIA. 



Buffon has justly declared tliat these are the prettiest and most 

 charming of all the Monkeys ; they are much sought after, but as 

 they are very rare, few of them are seen in Europe. Isidore 

 Geoifroy Saint-Hilaire speaks in the following terms of the 

 Saimiri : — 



" Its physiognomy is that of a child ; it has the same expression 

 of innocence, sometimes the same sly smUe, and always the same 

 rapidity of transition from joy to sorrow ; it feels disappoiutment 

 very acutely, and testifies it by crying. Its eyes become be- 

 dewed with tears when it is vexed or frightened. It is prized 

 by the natives for its beauty, its amiable manners, and the gentle- 

 ness of its disposition. Its activity is astonishing, though its 

 movements are always full of grace. It is incessantly occupied 

 in play, jumping, and catching insects, especially spiders, which it 

 prefers to all kinds of food." 



Humboldt informs us that the Saimiri listens with the greatest 

 attention to people who ask it questions, and that it even stretches 

 out its hands towards their lips, as if to catch the words that 

 escape from them. 



Genus Nocthom. — The names of Nocthora and Nyctipithecus, 

 given by Fr. Cuvier and by Spix to animals of this genus, in- 

 dicate their essentially nocturnal or crepuscular habits. These 

 little Monkeys sleep all the day, either in the cavities of trees or 

 in the midst of the thickest foliage, and it is only towards sunset 

 they come forth. Their eyes are very large and phosphorescent — 

 that is, luminous in the dark. Humboldt says that these Mon- 

 keys are monogamous, and always live in couples ; but Spix 

 assures us they go together in bands. 



The Nocthora subsist on insects and small birds. Their voice 

 is powerful, and, according to Humboldt, resembles that of the 

 Jaguar. The best known species, the Douroucouli [Nyctifithecus 

 trwergatiis), takes its name from the cry it emits during the night, 

 when hunting in the woods. The Nocthora inhabit the banks of 

 rivers in Peru, Bolivia, Brazil, and Paraguay. 



Genus Saki. — ^The Sakis bear much resemblance to the Sapajous ; 

 but they are distinguished from them by their non-prehensile tail, 

 which is covered with long and very bushy hair, a circumstance 

 which causes them to be called Fox-tailed Monkeys. They in- 

 habit thickets, solitary or in troops, and are more crepuscular than 



