368 Animal L ife and Intelligence. 



valuable observations. This monkey on one occasion got 

 hold of a hearth-brush, and soon found the way to unscrew 

 the handle. After long trial, he succeeded in screwing it 

 in again, and throughout his efforts always turned the 

 handle the right way for screwing. Having once succeeded, 

 he unscrewed it and screwed it in again several times in 

 succession, each time with greater ease. A month after- 

 wards he unscrewed the knob of the fender and the bell- 

 handle beside the mantelpiece. Commenting on these 

 actions, Mr. Eomanes speaks* of '*the keen satisfaction 

 which this monkey displayed when he had succeeded in 

 making any little discovery, such as that of the mechanical 

 principle of the screw." 



I once watched, near the little village of Ceres, in South 

 Africa, a dung-beetle trundling his dung-ball over an 

 uneven surface of sand. The ball chanced to roll into a 

 sand hollow, from which the beetle in vain attempted to 

 push it out. The sides were, however, too steep. Leaving 

 the ball, he butted down the sand at one side of the hollow, 

 so as to produce an inclined plane of much less angle, up 

 which he then without difficulty pushed his unsavoury 

 sphere. 



Now, it seems to me that, if we say, with Mr. Eomanes, 

 that the brown capuchin discovered the principle of the 

 screw, we must also say that the dung-beetle that I observed 

 in South Africa was acquainted with the principle of the 

 inclined plane. Such an expression, I contend, involves 

 an unsatisfactory misuse of terms. A mechanical principle 

 is a concept,! and as such, in my opinion, beyond the 

 reach of the brute — monkey or beetle. That of which the 

 monkey is capable is the perceptual recognition of the fact 

 that certain actions performed in certain ways produce 

 certain results. Why they do so he neither knows nor 

 cares to know. What the brown capuchin discovered was 



• " Animal Intelligence," p. 497. 



t Mr. Eomanes regards it as, in the case of the capuchin, a recept But 

 •when he speaks of a generic idea of causation, and generic ideas of principles, 

 and of qualities as recepts, I find it exceedingly difficult to follow him. They 

 seem to me to be concepts supposed to be formed in the absence of language. 



