THE ANIMATE ENEMIES OF THE FOREST. 77 



attacked the trunk and large branches, and the latter, which 

 was seldom absent, found a lodgment in the smaller branches. 

 Their habits were described as follows : 



" When the female of the typographic species is ready to de- 

 posit her eggs, which occurs about the middle or latter part of 

 spring, sooner or later, according to the temperature, she pene- 

 trates the bark, and bores, almost invariably from below up- 

 wards, a gallery that is cut along the outer layer of the sap- 

 wood, depositing her eggs, as she advances, on the right side 

 and the left. These are so quickly developed that the first 

 larvae will have themselves made considerable galleries before 

 the parent has finished. Each of these larvae digs a separate 

 path of its own, more or less inclined to that made by the 

 mother, and at the end of two or two and a half months they 

 are transformed to a perfect insect, which in turn proceeds to 

 lay a new lot of eggs, and, if favored by the heat of August, 

 these are sometimes found more destructive than the first. 

 This second growth is matured towards the end of September 

 or beginning of October, and will be ready to resume opera- 

 tions in the following spring. In the mean time they pass the 

 winter under the mosses and in the crevices of the bark, where 

 they endure the severest frosts of winter, for the perfect insect 

 is as hardy as its larvae are tender. 



" The number of eggs deposited by one insect varies from 

 twenty to one hundred and twenty or one hundred and thirty, 

 and from this bark we may make some very instructive estimates. 

 Suppose that each laying of sixty eggs produces specimens in 

 which the sexes are equal, one female will have produced 

 thirty others, which would each before the end of the year be 

 represented by eighteen hundred of their kind. Half of these, 



7* 



