ABOUT CHRYSALIDS 233 



plained ; nor have the structure, form, and position 

 of the belt been taken into consideration. No 

 underlying structure, as far as I am aware, has 

 been found related to it alone ; and as an external 

 covering of an eye its structure is midway between 

 that of the caterpillar and the perfect insect. 

 May it be a relic of the past, the external sign 

 of what once was ? Are we to look upon this as 

 one hint that the archaic butterfly in its transfor- 

 mations passed through an active pupal state, like 

 the lowest insects of to-day, when its limbs were 

 unsheathed, its appetite unabated, and its daily 

 necessities required the use of a compound eye, 

 such as would result from the multiplication and 

 conglomeration of simple eyes within the normal 

 ocellar field of the larva ? This, it is true, is 

 merely speculation ; but whatever explanation of 

 the structure of this glassy band is given must 

 account for its form and its relation to the larval 

 row of tubercles. 



There is another peculiarity in the head of 

 certain chrysalids which demands our attention 

 and an explanation of its cause, since it is found 

 in some groups and not in others. On either side 

 of the front of the head there is often a roughened 

 angulate or conical projection, bearing no relation 



