160 ARBOREAL MAN 



important tactile organ from the seat of the nasal scent im- 

 pressions is important, for other things than those smelled 

 out or bumped into come constantly under examination. 

 The evolution is evidently harmonious in its details. 

 The more the fore-limb becomes emancipated, the less 

 is the hand called upon for menial duties which in other 

 stocks necessitate the development of skin thickenings, 

 pads, callosities, or hoofs. It is the freed hand which is 

 permitted to become the sensitive hand, and it is the 

 freed and sensitive hand which now, so to speak, goes in 

 advance of the animal and feels its way as it climbs 

 through life. The animal no longer smells out an object, 

 subsequently to feel it with its nose; but it feels with its 

 hand some object which comes within its reach in the 

 ordinary course of its arboreal activities, and it may or 

 may not subsequently add to its knowledge of the object 

 by smelling it. Tactile impressions gained through the 

 hand are therefore perpetually streaming into the brain 

 of an arboreal animal, and new avenues of learning about 

 its surroundings are being opened up as additions to the 

 old olfactory and snout-tactile routes. With the develop- 

 ment of the power of grasp, new and great possibilities 

 come in. Much may be learned of an object that can be 

 felt by the hand; much more of an object that may be 

 grasped, lifted and examined in the hands. When an 

 object can be grasped and lifted it can be examined from 

 every point of view, and the eyes must play a large part 

 in this examination. Its whole outline, the texture of 

 its surface, its hardness or softness, its size, temperature, 

 and weight, can all be ascertained. It is difficult for 

 us, with our perfected cerebration, to appreciate the 

 difference which the power to grasp an object makes to an 

 animal attempting to learn the nature of objects with 

 which it comes in contact, but we may be sure that the 

 difference was very great, and was made greater when 

 the power to pick up the object and to examine it from 

 all points of view was added. 



