44 DECEPTIVE DEVICES 



forward by little starts ; tliey seem to glide by lit- 

 tle jerks in a very slow and measured way. The 

 caterpillars in which I have noticed this habit are 

 the Blue-eyed' Grayling (Cercyonis alo^De), the 

 Orange Sulphur (Eurymus eury theme), and the 

 Green-clouded Swallow-tail (Euphoeades troilus) ; 

 it is most conspicuous in the last. 



Perhaps of all our caterpillars there are none 

 which have so many means of defense in habit or 

 protective device as the species of Basilarchia, and 

 this altogether in addition to their coloring. At- 

 tention has already been drawn to this. It may be 

 well, however, to summarize here some of the more 

 peculiar ways by which it protects itself. In the 

 first place it moves about with little starts, much 

 as the Green-clouded Swallow-tail (Euphoeades 

 troilus) and the others we have mentioned, its 

 head all the while trembling as if it had the palsy ; 

 then, when disturbed, it will throw the front half 

 of its body about like a whip, lashing its sides with 

 great violence and fury, an operation which must 

 most eifectually drive away many of its smaller 

 foes at least. These points refer to its active 

 movements, but besides we have its curious habit 

 of living upon the extremity of the uneaten midrib 

 of the leaf upon which it is feeding ; its construe- 



