How Animals Talk 



face to face with the same problem, and perhaps 

 also the same answer. Sometimes the mating call 

 is addressed to the outer ear, as in the drumming 

 of a cock-grouse or the whine of a cow-moose; 

 but frequently a mate appears when, so far as we 

 can hear, there is no audible cry to call him. 

 How do the butterflies, for example, know when 

 or where to seek their other halves? That their 

 meeting is by chance or blunder or accident is a 

 theory which hardly endures an hour's observa- 

 tion. In the early spring I take a cocoon from a 

 certain corner of shrubbery and carry it to my 

 house, and there keep it till the end softens, when 

 I put it into a box with a screened top and hang it 

 out under the trees. Presently a gorgeous moth 

 crawls out of the cocoon ; and hardly has she begun 

 to wave her wings to dry them when the air over 

 the screen is brilliant with dancing wings, the 

 wings of her would-be mates. And the thing is 

 more puzzling to me because I have never found a 

 cocoon of that kind in my immediate neighbor- 

 hood ; nor have I seen a single cecropia this season 

 until the captive called them. 



How they find her so promptly is a problem that 

 I cannot solve. It may be that the call is wholly 

 physical or sensible, that some fine dust or aroma 

 is sent forth on the air currents, and the sensitive 

 nerves of other moths receive and respond to it; 



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