THE CANKER-WORM. 463 



females lay their eggs (Fig. 230, natural size and magnified) 

 upon the branches of the trees, placing them 



i , . ^ „ Fig. 230. 



on their ends, close together ni rows, fonn- 

 inn- clusters of from sixty to one hundred 

 eo-o-.s or more, Avhicli is the number usually 

 laid by each female. The eggs are glued 

 to each other, and to the bark, by a grayish varnish, which 

 is impervious to water ; and the clusters are thus securely 

 fastened in the forks of the small branches, or close to the 

 young twigs and buds. Immediately after the insects have 

 thus provided for a succession of their kind, they begin to 

 languish, and soon die. The eggs are usually hatched be- 

 tween the first and the middle of May, or about the time 

 that the red currant is in blossom, and the young leaves 

 of the apple-tree begin to start from the bud and grow. 

 The little canker-worms, upon making their escape from 

 the eggs, gather upon the tender leaves, and, on the occur- 

 rence of cold and wet weather, creep for shelter into the 

 bosom of the bud, or into the flowers, when the latter ap- 

 pear. As this treatise may fall into the hands of persons 

 who are not acquainted with the habits and devastations 

 of our canker-worms, it should be stated that, where these 

 insects prevail, they are most abundant on apple and elm 

 trees ; but that cherry, plum, and lime trees, and some 

 other cultivated and native trees, as well as many shrubs, 

 often suffer severely from their voracity. The leaves first 

 attacked will be found pierced with small holes ; these be- 

 come larger and more irregular when the canker-worms 

 increase in size ; and, at last, the latter eat nearly all the 

 pulpy parts of the leaves, leaving little more than the midrib 

 and veins. 



A very great difference of color is observable among 

 canker-worms of different ajies, and even amono; those of 

 the same age and size. It is possible that some of these 

 variations may arise from a difference of species ; but it is 

 also true that the same species varies much in color. When 



