190 APPENDIX. 



of the cork are varnished, and a label pasted around the 

 portion of the cork which enters the tube, thus guarding 

 both sjoecimen and label from dust, and the latter from 

 loss or misplacement. After two or three days the cork 

 Avith the caterpillar attached is placed in its corresponding 

 tube, and the tube may be freely handled. 



Modifications of this system will occur to every one. 

 Dr. Gemminger uses a syringe for the extraction of the 

 contents as well as for the inflation of the emptied skin. 

 For an oven, the Vienna entomologists employ an ordi- 

 nary gas-chimney, open at both ends and inserted in a 

 sand-bath, which prevents, perhaps, the danger of too 

 great heat. 



In rearing caterpillars for the after-stages, care must 

 always be taken to provide in season a suitable place in 

 the breeding-cage for the chrysalis to suspend itself: a 

 twig for such as prefer such situations; a bit of shingle 

 near the top of the cage for those that suspend themselves 

 by the tail, or fasten themselves preferably to flat surfaces; 

 leaves for those tliat construct some sort of a cocoon. The 

 search for chrysalids in the open air is not likely to meet 

 with great success excepting in a few instances, such as 

 the imported cabbage butterfly, whose chrysalids can be 

 found in only too great abundance beneath palings or on 

 the under edge of clapboards on farm-houses; those of the 

 blues and their allies may often be found beneath stones, 

 but one must be an enthusiast to follow the search at all 

 successfully; such as fall into the hands of the general 

 entomologist must be counted as clear gain; yet these will 

 often repay him who studies also the parasites of butter- 

 flies, so often are they found to be infested. 



The preservation of chrysalids with their colors is easy 

 for all that are not of some green tint; and these are few. 

 Long-lived chrysalids are not easily killed excepting by 

 extreme dryness. Some will survive a twelve hours^ plunge 



