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THE YOUNG NATURALIST. [ February 



THE ORIGIN AND LOSS OF THE WINGS OF 



INSECTS. 

 By LINN^US GREENING. 



Concluded from p. 15. 

 part ii. — The Loss of Insects' Wings. 



Having seen by what means the Insecta came into possession of 

 their wonderful organs of flight and the immense period of time 

 necessary for their perfect development, we may well be surprised to 

 find that some of them have now positively found it advantageous 

 not to use them, owing to the changed conditions under which they 

 exist. I maintain that use and dis-use are the most important factors 

 in the increase or diminution of organs, just as in the far off Silurian 

 epoch, flying insects had no flying enemies to contend with, and as the 

 power of flight enabled them to get increased variety and quantity of 

 food, all tending to add to the general vigour of the animal and the 

 increase of its organs of flight ; so now when insects have so many 

 enemies in the air as well as on land and water, to say nothing of the 

 collector ; we find that many have found it useful to discard the once 

 advantageous wings, which have been lost through generations of dis- 

 use. As I said at the beginning of this subject, it was the apterous 

 females of our Lepidoptera that first called my attention to this 

 question, and so I shall take them as the first illustration of those 

 who have lost their wings through dis-use. We find in several species 

 of our British Lepidoptera that the females are apterous or at least 

 so nearly so, that the once functional wings are represented by 

 the merest rudiments. It may be asked, nay in fact it has been sug- 

 gested, that these rudiments are really nascent wings, i.e. not 

 the remains of lost wings, but the first beginnings of new ones. No 

 competent naturalist would for one moment entertain this idea, which 

 has only been pushed to the front by those who did not understand the 

 structure of these organs, and is an illustration of the truth of the 

 saying " a little knowledge is a dangerous thing." 



It has also been suggested that these apterous females were the 

 descendants of crippled mothers ; but this is a quite untenable posi- 

 tion, for rarely if ever does a mutilation pass on to the progeny. For 

 this theory to hold good we must assume a continuous series of imper- 

 fect or crippled parents, which is quite contrary to any known law of 



