20 DESTRUCTIVE POWERS OF INSECTS. 



agree with Mr. M'Leay in calculating the existing 

 number of species at four hundred thousand ! * 



Even here the treasures of the Entomologist are not 

 exhausted. The geologist finds in shale the im- 

 pressions of insects, stamped on the yielding surface 

 of the mineral, and there presenting their correct 

 and enduring portraiture. In amber he discovers 

 insects in the very attitudes of life, and of species 

 which have long since become extinct. These repre- 

 sentatives of a former insect world are to the Ento- 

 mologist what the skeletons and ornaments of Pompeii 

 would be to the antiquarian, or fossil fishes to the 

 ichthyologist. They are the records of another era, 

 unfolded for our study. 



We must recollect also, that an accurate knowledge 

 of the habits and economy of insects is of considerable 

 importance to the comfort, and to the security of 

 man. Though each may individually be regarded as 

 insignificant, their numbers compensate for their di- 

 minutive size, and thus banded together, they become 

 absolutely irresistible. Wilson, in his " American 

 Ornithology," says, " Would it be believed that the 

 larvae of an insect or fly, no larger than a grain of 

 rice, should silently and in one season destroy some 

 thousand acres of pine trees, many of them from two 

 to three feet in diameter, and a hundred and fifty 



* Introduction to Entomology, vol. iv. p. 476. 



