Physical Evolution of Man 585 



laying; of its low determined guttural notes when fighting; of 

 its "purring" expressions when quieting its young beneath 

 its wings; of its sharp inquisitive utterances when stalking in 

 search of food; of its shrill sudden shriek when suddenly set 

 upon and chased by an adversary; of its long-drawn warning 

 exclamation or drawl when a supposed bird of prey flies across 

 the sky. Regarding these Houzeau writes (182: II 348): 

 "Now since the hen does not utter its warning voice after 

 laying, nor its purring notes when in search of food, but each 

 appropriate to a definite occasion and as definitely understood 

 by others of its species even when not within sight, it is strongly 

 suggested that in each case there is an exact concept formed in 

 the brain of the bird that stimulates to an exact expression. 

 Were we dealing with a human being, the writer believes that 

 no one would doubt or criticize this, unless very strong proof 

 were advanced." 



Hobhouse (184^: 281), in contrasting the intelligence of the 

 highest animals other than man, with man himself, says: "We 

 may suitably attack this problem, by inquiring first, what 

 precisely the use of language adds to the practical intelligence 

 which we have described An intelligent dog or ape can, if 

 the evidence which we have quoted is sound, use experience 

 intelligently, and even plan an adjustment of means to ends 

 with a certain measure of inventiveness. But it cannot de- 

 scribe what it does to us, nor so far as we know to another 

 individual of its own species." Here the writer accepts it that 

 these animals can originate a concept or plan of action, though 

 they cannot describe it. But when a cur, in danger of being 

 whijiped or kicked, flies and simultaneously utters its well 

 known cry, such is a definite though simple descriptive warning 

 to others of its kind that may be near. Similarly when the 

 hen purrs broodingly over its young, simultaneously spreads 

 its feathers even more expansively than before, and with its 

 beak pushes gently inward the protruding head of a wakeful 

 young one, it is describing alike to "another individual of its 

 own species" as well as to each human listener, the fairly 

 complex line of action mapped out in its brain. 



19* 



