154 THE CANADIAN ENTOMOLOGIST. 



As is well known by all aurelians, one considerable collection of 

 Abbot's drawings was published by Sir James Edward Smith in two 

 sumptuous folio volumes, but these comprise, as far as the butterflies are 

 concerned, only twenty-four species. This work made an epoch in the 

 history of entomology in this country. Besides this Abbot published 

 nothing. The article credited to him in Hagen's Bibliography was by a 

 Rev. Mr. Abbot, who wrote from England in November, 1798, when 

 Abbot was in this country. 



CHARACTERS OF PROTECTION AND DEFENCE IN INSECTS. 



BV A. R. GROTE, A. M., BREMEN, GERMANY. 



A few years since I described a colony of Spanner caterpillars 

 (Geometridce) belonging to an undetermined species, and the description 

 appeared afterwards in this journal. These larva? were remarkable 

 for their mimicry, in color and shape and attitude, of dead leaves. 

 There could be no question that they belonged to the category of 

 protective appearance, to which so many green and brown tinted 

 larvse belong, which share these " cosmical colors." In studying 

 these larvae we must consider their color, shape and attitude separately. 

 The larva? of most of the Hawk Moths belong to this category. The 

 caterpillar in repose, or at the approach of danger, assumes a rigid attitude 

 in which it resembles a leaf on a branch of the food plant. The 

 markings along the back often assist this resemblance. The only motion 

 is that imparted by the swaying of the plant on which it rests. When 

 disturbed, the caterpillar of Thyreus Abbotii throws itself by jerks from 

 side to side and gives out a crepitating noise. It looks then somewhat 

 snake-like. 



The second category is that of defensive appearance. Highly colored, 

 red and yellow larvae, belong many of them to this category, as also 

 those armed with spines and prickles. These would seem to court obser- 

 vation, which they further aid by their restlessness. It is probable that, 

 by their gaudy appearance, they inspire distaste or fear in their natural 

 enemies. The caterpillars of Orgyia are not eaten by birds, nor are 

 those of Abraxas. By simulating obnoxious species it has been shown 

 that several kinds of butterflies escape destruction. From these two points 

 of view the appearance of insects must be studied, but it by no means 

 follows that the means to the end have been always perfectly attained. 



