GENERAL CHARACTERISTICS. 



71 



recurved canines. The premolars in addition 

 to the sharp middle point have lateral cusps, 

 the molars are sharply indented and are pro- 

 vided with a narrow internal heel or process. 

 The forehead, as in the saimiri, is very flat, 

 and the brain-case is oval, the broad part 

 behind. The vertebral column is exactly 

 that of a mammalian quadruped. The tail 

 is always very long, and is carried in a 

 hanging position. 



The fore-limbs are paws with sharp claws 

 on the digits ; the thumb is non-opposable. 

 In the hind-limbs, on the other hand, the 

 hallux, which, to be sure, is only slightly 

 developed and by no means a "great toe," 

 is opposable, but has a flat nail, while the 

 other four toes, like all the digits of the fore- 

 limbs, have sharp curved claws. 



The Arctopitheci comprise about twenty 

 known species, which, though differing from 

 each other sometimes rather strikingly in the 

 character of their hair-covering, present other- 

 wise such slight divergences that they are all 

 referred to one genus, Hapale.^ Their range 

 extends northwards into Mexico. 



They live socially not only in the primeval 

 forests but also in sparse clumps containing 

 lofty trees, and their whole behaviour re- 

 sembles that of our squirrels. They pass the 

 night sometimes in pairs, but sometimes also 

 in companies in hollow trees, which they line 

 internally with moss and leaves, and they 

 always choose hollows with narrow entrances, 

 in order to protect themselves as far as 

 possible from the marten-like beasts of prey 

 which, as well as serpents and rapacious 

 birds, eagerly seek after them. Like our 

 squirrels they jump but seldom, and in hasty 

 flight from one tree-top to another prefer 

 to run down the stem of the one tree and 

 then, hastily crossing the interval between 

 the two on the ground, clamber up the other. 

 If they happen to be observed in climbing 

 a tree they know how to hide themselves 



'Sometimes they are divided into two genera, Hapale and 

 Midas. — Tk. 



dexterously behind the trunk of the tree or 

 behind its larger branches. 



They are extremely shy, timid little crea- 

 tures. Their body is at most one foot in 

 length. Unlike other monkeys they produce 

 two or three young at a birth, and these the 



Fig. 23. — The Silky Marmoset {^Hapale rosalia). page 72. 



female drags about with her, or, when she 

 becomes tired, hangs on to the male, who 

 then behaves towards them in a quite mater- 

 nal manner. If it must be admitted that they 

 show great skill in moving about and pro- 

 viding for their own safety, that is about all 

 that can be said of their mental qualities. 

 Their food consists almost exclusively of 

 small animals, insects, spiders, &c., and sweet 

 vegetable substances are eaten only as a 

 relish. 



Some species are very frequently brought 

 to Europe and tended as in their native land. 

 But it is only very slowly and with much 

 difficulty that they learn to know their 



