THE QUESTION OF HIBERNATION. 17 



from mistaken identity, we will here quote part of a letter received 



from Professor Willet, who has particularly interested himself in this 



Bubject. ^' I have received to-ni<^ht," writes Professor Willet, ^'from 



Eev. Kobert Harris, of Cairo, Thomas County, Georgia, a small tin box 



inclosing 25 chrysalides, which I forward yoii by mail. Mr. Harris is 



an ardent believer in the subterranean hibernation of the chrysalis of 



Aletia argillacea. I transcribe the portion of his letter pertinent to the 



case: 



' Cairo, Ga., February 22, 1879. 



* Washington's birthday and victory. Perseverantia vincit. The facts 

 drive ''analogy" to the wall. Here they are: 25 cottou-worm chrysa- 

 lides ploughed u]) out of the ground in a field that was riddled by the 

 insects last fall. 



'This is unimpeachable evidence, and in the opinion of the court is 

 amply sufficient to convict the prisoner.' 



" The chrysalides," continues Professor Willet, '^ appear to my eye 

 very like Aletia chrysalides which I have in spirits, and I await your 

 verdict with interest." 



The chrysalides referred to in this instance resemble those of Aletia so 

 thoroughly in form, size, and general appearance that they might have 

 been mistaken therefor even by some entomologists ; yet, from certain 

 minute structural differences, easily observable with a good lens, we were 

 able at once to decide that they belonged to another insect, the Aspila 

 virescens oiYahiicm^ a beautiful moth, with olivaceous primaries, marked 

 with three distinct, pale, transverse lines, relieved by coincident deeper 

 shades, the translucent green larva of which, speckled with minute, pale, 

 fleshy elevations, we have found feeding on Solanum siegUnge in Saint 

 Louis. ^' 



There are many species of night-flying moths which go through their 

 transformations beneath the ground, and there hibernate in the chrysalis 

 state. The leaves of the cotton-plant are palatable to a very large num- 

 ber of such, while the Boll-worm {Heliothis armigera) and the ^-Grass- 

 worm" (Laphygma frugiperda), which thus transform, are sometimes 

 xerj abundant in a cotton-field. It is not at all surprising, therefore, 

 that the chrysalides should be plowed or dug up in land planted to cot- 

 ton. All of them, upon careful scrutiny, will be found to differ from the 

 chrysalis of Aletia, which may be distinguished by its slender form, and 

 particularly by the tip of the body with its armature, as shown in Fig. 4. 

 In short, the nature of the Aletia chrysalis effectually prevents it from 

 working beneath the ground, except where, dropping out of its cocoon, 

 it happens to fall into some crack or crevice, and thus wriggle beneath 

 the surface. It is also contrary to aU analogy that a chrysalis normally 

 found above ground in a cocoon should work beneath the soil; for all 

 insects that pupate under ground descend while in the larva state. 



Experiments which we have repeatedly made prove that the Aletia 

 chrysalis, when placed under ground, either rots and perishes or the 

 63 CONG 2 



