472 LEPTHANDEDNESS. 



the mucli greater lateral development of the chest and abdomen of 

 the human figure, in order to adapt it to the erect posture, as con- 

 trasted with the great lateral flattening of the trunk in quadrupeds. 

 The equipoise is therefore more disturbed in man than in the quad- 

 ruped ; and it may be observed that the same consideration applies 

 to the child, in whom the chest is at first narrow, and in whom it 

 undergoes rapid increase of breadth when the child begins to walk : 

 ■the period at which, according to the gravitation theory, the predom- 

 inance of the right hand should begin to be developed. To this 

 reason why the position of the centre of gravity to the right side 

 should have more influence in man than in the quadruped, may be 

 added the fact of the erect posture, enabling the gravitating influence 

 to operate at once on the whole one side of the body." 



The necessities of the monkey as a climber no doubt tend to 

 bring all its limbs into constant use ; but possibly careful study of 

 the habits and gestures of monkeys may disclose, along with ambi- 

 dextrous facilities, some traces of a preference for the limbs on the 

 one side. The elephant has been repeatedly afl&rmed to betray a 

 strongly marked rightsidedness ; and this has recently been reiterated 

 in a communication made by Mr. James Shaw to the Anthropo- 

 logical sub-section of the British Association, where he noted the 

 " curious fact that elephants have been frequently known to use the 

 right tusk more than the left in digging up roots, and in doing 

 other things." But the statement is vague, and, even if confirmed by 

 adequate proof, can scarcely be regarded as the equivalent of right- 

 handedness. I formerly referred to the greater development of the 

 left tusk of the walrus- in a specimen in the Museum of the University 

 of Toronto. I have since learned of other examples of this ; and am 

 assured by an old Hudson's Bay factor that it is of frequent occur- 

 rence both in the walrus and narwhal. On this subject Dr. Struthers 

 remarks : ." When we examine the instances of unequal development 

 on the two sides, among animals constructed on the symmetrical 

 plan, it does not appear that there is any preference in nature for 

 one side more frequently than for the other. Among the mammalia, 

 we observe that it is the left tusk of the narwhal which is normally 

 so greatly developed. In birds the ovary and oviduct which are 

 developed are almost always the left. In serpents, the lung which 

 is so much developed, compared with the other, is the right. Among 

 fishes, the pleuronectidse, or flat fishes, present a remarkable a-sym- 



