THE OAK EGGEE MOTH. 289 



perceptible on one side alone, eacli hole representing at least one 

 ichneumon fly which had made its escape after fulfilling its 

 destructive mission. 



The handsome Oak Eqgee Moth [Oastropacha guercus) affords 

 another example of the pensile cocoon. Of these insects also I 

 have had great numbers; and some specimens of the moth, 

 chrysalis, and cocoon are now before me, the cocoon unchanged 

 by the eighteen years which have elapsed since it was made, but 

 the moth sadly faded, after the manner of its kind when exposed 

 to the action of light This insect, by the way, is one of those 

 which suffer the most from the fumes of sulphur, a lesson which 

 I long ago learned from experience. Having been told that the 

 best method of killing moths was to expose them to the fumes of 

 burning sulphur, I invented an apparatus which would cause the 

 insects to be enveloped in dense fumes, while the heat of the 

 burning sulphur was carried off in another direction. 



Of its efficacy as a means of destruction no complaint can be 

 made, inasmuch as it destroyed the insect in a very few moments ; 

 but as it likewise discharged the colours, its use was soon given 

 up. AU the beautiful scarlets lost their tone, and became pale 

 orange, and in the case of the Oak Egger and similar moths, the 

 warm dim of the wings changed to dirty yellow. Moreover, the 

 sublimated sulphur was sure to rest upon the wings, and to 

 destroy their delicacy. 



Camphor, which is so largely and so wrongly used in cabinets, 

 is liable to the same objection. Its volatility is extreme, a large 

 lump vanishing in a wonderfully short time when exposed to 

 the air. The pieces of camphor used in cabinets continually 

 need renewal, and the question frequently arises. Where has the 

 camphor gone? The answer may be found in the dimmed 

 glass, on which a deposit has been left, and which is so difScult 

 to be cleaned, as well as on the inclosed insects, the lustre of 

 whose bodies is sadly marred by the same substance. 



Large as is the caterpillar of the Oak i^er moth, it is con- 

 tracted into a comparatively small chrysalis when it assumes 

 the pupal state, and makes a cocoon which only allows enough . 

 space for the pupa and the cast larval skin. The form of the 

 cocoon is egg-shaped, whence the name of Oak Egger, and its 

 substance is rather peculiar, being thin, hard, and rather brittle 



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