i873-] Notices of Books. 115 



animals. It has been thought by some to be a special endow- 

 ment for the purpose of expressing modesty or shame, but Mr. 

 Darwin objects to this view, because it occurs in dark races, 

 when it is hardly visible, and also because shyness is the most 

 frequent cause of blushing, and this is of no use, and makes both 

 the actor and spectator equally uncomfortable. The theory 

 adopted is, that blushing is caused by self-consciousness directed 

 chiefly to our personal appearance, and is therefore generally 

 exhibited in the face, to which attention is most directed, and the 

 skin of which is very sensitive. Much evidence is adduced to 

 show that.attention directed to any part or organ can affect its 

 condition or action, and this is the physiological fact on which 

 the explanation rests. Great confusion of mind often accompanies 

 blushing, and is supposed to be caused by it. But it seems more 

 probable that it is caused by the whole attention being so power- 

 fully directed to ourselves as to interfere with the action of the 

 mind in any other direction. A remarkable instance of this 

 confusion is given by Mr. Darwin on the authority of an eye- 

 witness: — 



" A small dinner party was given in honour of an extremely 

 shy man, who, when he rose to return thanks, rehearsed the 

 speech, which he had evidently learnt by heart, in absolute 

 silence, and did not utter a single word ; but he acted as if he 

 were speaking with much emphasis. His friends perceiving how 

 the case stood, loudly applauded the imaginary bursts of 

 eloquence whenever his gestures indicated a pause ; and the 

 man never discovered that he had remained the whole time com- 

 pletely silent. On the contrary, he afterwards remarked to my 

 friend with much satisfaction that he thought he had succeeded 

 uncommonly well." 



It has been an objection to Mr. Darwin's theory of the " Origin 

 of Species," that the rattlesnake warns its prey of its vicinity, 

 and that such a habit could not possibly have been acquired by 

 natural selection. In a very interesting discussion on the means 

 of exciting fear in an enemy, Mr. Darwin gives a fuller statement 

 of his views on this subject than he has done in any of his former 

 works. He finds that various kinds of reptiles inflate themselves, 

 hiss, open their mouths, and assume a ferocious aspect as a 

 means of protection against attack. The cobra dilates its hood 

 when alarmed or excited, and the puff adder swells and hisses 

 with a sound hardly distinguishable from the rattle of the rattle- 

 snake. He believes, therefore, that all these various sounds and 

 appearances are warnings to would-be devourers that the creatures 

 who produce them are dangerous. The rattle of the rattlesnake 

 is said to imitate closely the sound of a cicada inhabiting the 

 same region, and it has been supposed that it serves the purpose 

 of attracting insect-eating birds as the snake's prey; but this 

 view is rendered improbable by the fact that the snake rattles 

 when alarmed or threatened. If it is proved to be a warning to 



