40 STUDIES IN LIFE AND SENSE. 



supports. There seems little doubt that the habitual attitude of the 

 ape is on " all-fours." A monkey will often raise itself on its hind 

 legs when prompted by curiosity and for the convenience of looking 

 at any object ; but the position is a constrained one, and the animal 

 soon returns to its " all-fours," or to its sitting posture. The con- 

 formation of the monkey's body, and the muscular arrangements of 

 its haunch, loins, and hind limbs, are not adapted for the mainte- 

 nance of the erect posture. Indeed, if we consider for a moment 

 the adaptation of the animal's foot to the uses of a hand, we may 

 readily enough conceive why the erect posture is one for which the 

 monkey-race is absolutely unfitted. Probably any cause which 

 lessened the use of the foot for grasping, would tend towards the 

 development of the powers and faculties through which the erect 

 posture could be assumed. But the entire organisation of the ape 

 militates against the idea that this posture can be readily or easily 

 assumed by the quadrumanous tribes: since not only muscles, but 

 bones also, and indeed the entire framework of the animal, would 

 require to undergo very considerable modification before the human 

 posture could be readily or without effort maintained. 



The order of monkeys was included by Linnaeus along with the 

 human group under the common designation of Primates. To this 

 arrangement, as expressive of real and natural affinities between the 

 two orders, modern zoology has returned. The structural gaps 

 between man and apes may seem wide and yawning to those who do 

 not realise that one and the same type of structure runs unbrokenly 

 through the Vertebrate races, from fish, through frog, reptile, and bird, 

 up to quadruped and man. As the same general type characterises 

 all the Vertebrate animals, so that mere special modification of it 

 which marks the whole quadruped-class is again reflected with equal 

 clearness in forms so divergent as the whale, dog, horse, bat, ape, and 

 man. And as, lastly, the quadruped-form exhibits its own rise and 

 advance as we proceed from its lower to its higher forms, so again 

 we must note that the same high development is reflected not singly 

 in human structure, but conjointly in the quadrumana and in man. 

 In other words, ape-structure is an advance upon that seen in other 

 quadrupeds, but it is an advance in which humanity has shared and 

 beyond which human development has, in turn, proceeded. Only 

 some such ideas as these, which bargain for the idea of an unbroken 

 and continuous development of quadruped-life, and, indeed, of life 

 of every grade likewise, can satisfy the modern scientific aspiration 

 after a true cause at once of life's likenesses and of living variety. 



Natural historians have divided the monkey-tribe into three well- 

 known groups. These subdivisions are characterised each by highly 

 distinct variations in structure, and in habits as well. The lowest of 

 the three groups includes animals which are only doubtfully classified 



