46 STUDIES IN LIFE AND SENSE. 



may account for the increased and special mental calibre of man 

 himself. 



The special features of the Platyrhine apes are so numerous, that 

 the most superficial notice of the more prominent forms can alone 

 be attempted here. The howlers (Mycetes\ for example, derive 

 their popular name from their loud voice, which resounds for 

 immense distances through the South American forests. These 

 monkeys are the largest of the New World apes, and their special 

 peculiarity consists in the possession of a bony " drum " connected 

 with the larynx or organ of voice. Through this drum, which acts 

 like a sound-chamber, the voice of the Mycetes is rendered trebly 

 powerful, and resounds through the Amazonian forests for miles. 

 The agile spider monkeys of America remind us of the gibbons of 

 the Eastern Archipelago in their agility and in the possession of 

 long slender limbs. It is the spider monkeys which are credited 

 with linking themselves together from the bough of a tree by the 

 fore limbs and tails so as to form one animated chain. This chain 

 is then set swinging until the individual which represents the end of 

 the chain is enabled in the course of the oscillations to grasp the 

 branch of a tree on the opposite side of the river or ravine which 

 the tribe desires to cross. Amongst the Sakis certain very curious 

 features in the hairy covering of the body are to be noticed. One 

 form, the Couxio, possesses a well-developed beard, which, being of 

 a deep black hue, gives to the monkey a most singular appearance. 

 The Yarke presents a still more curious feature in that the head of 

 the females alone is covered with long hair. Another form is bald- 

 headed, and possesses a rubicund face, whilst the body is covered 

 with white hair. The night monkeys {Nyctipitheti) possess the face 

 surrounded by a ruff of hair, and the eyes, as is usual in animals of 

 nocturnal habits, are of very large size. 



Turning now to the last group of the monkey-order, we find the 

 apes of the Old World (excepting the lemurs already noticed) to be 

 included in the division known as that of the Catarhina. This latter 

 name has reference to the oblique or slanting conformation of the 

 nostrils in these apes. The nostrils, as one may readily see on look- 

 ing at a baboon, a bonnet monkey, or a common macaque, slope 

 from the brow to the lips. They are placed close together, and 

 the broad partition seen in the New World apes is replaced by a 

 narrow one. We enter the domain of the " anthropoid," or man-like 

 apes, when we commence the investigation of the Catarhine monkeys. 

 It is in this group that we certainly discover the nearest approach to 

 human structure as a whole ; although it should not be forgotten that 

 this division includes forms of widely varying degrees of organisa- 

 tion, and by no means exhibits a uniformly high structure through- 



