HABITS OF THE CATERPILLARS 85 



Several cases are on record where in crossing railway tracks 

 they have impeded the progress of trains by making the rails 

 slippery as the bodies were crushed. One case which has 

 been vouched for by the entomologists of the United States 

 Department of Agriculture, after official investigation, is 

 reported in these words : 



" The rails on the Carolina Central railroad were covered 

 inches deep with caterpillars, so that for three days in succes- 

 sion trains were brought to a dead standstill, the driving- 

 wheels of the engine slipping round as though the rails had 

 been thoroughly oiled. The engineers were obliged to exhaust 

 the contents of the sand boxes before crossing the strip of 

 swamp from which the caterpillars seemed to come. The rails 

 and cross ties were said to be obscured from sight, and the 

 ground and swamps on each side of the track were covered 

 with millions of the crushed caterpillars, and from the mass an 

 unendurable stench arose." * 



Those Forest Caterpillars which utilize leaves in forming 

 their cocoons seem to have very little choice as to the leaves 

 employed. In Vermont, Miss Caroline G. Soule, to whom I 

 am indebted for a large number of observations upon this 

 insect, found cocoons made in the leaves of the following 

 plants : 



Apple Hawthorn 



Asparagus Horse Chestnut 



Barberry Hydrangea 



Cherry Maple 



Clover Mountain Ash 



Cut-leaved Birch Lilac 



Elm Pear 



Ferns Plum 



Fountain Plant Smoke Tree 



Fringe Tree Svringa 



Geranium Violet 



Grape Woodbine 



Grass 



Probably this list could be considerably increased by more 



* Insect Life. Vol. iii, p. 477. 



