188 INSECT ARCHITECTURE. 



birds, is proportioned, in the ingenuity of their arrange- 

 ments, to the weakness of the insect employing them. 

 Those species which multiply the quickest have the 

 greatest number of enemies. Bradley, an English natur- 

 alist, has calculated that two sparrows carry, in the course 

 of a week, above three thousand caterpillars to the young 

 in their nests. But though this is, probably, much beyond 

 the truth, it is certain that there is a great and constant 

 destruction of . individuals going forward ; and yet the 

 species is never destroyed. In this way a balance is kept 

 up, by which one portion of animated nature cannot usurp 

 the means of life and enjoyment which the world offers to 

 another portion. In all matters relating to reproduction. 

 Nature is prodigal in her arrangements. Insects have 

 more stages to pass through before they attain their 

 perfect growth than other creatures. The continuation of 

 the species is, therefore, in many cases, provided for by a 

 much larger number of eggs being deposited than ever 

 become fertile. How many larvae are produced, in com- 

 parison with the number which pass into the pupa state ; 

 and how many pupse perish before they become perfect 

 insects I Every garden is covered with caterpillars ; and 

 yet how few moths and butterflies, comparatively, are seen, 

 even in the most sunnj^ season ! Insects which lay few 

 eggs are, commonly, most remarkable in their contrivances 

 for their preservation. The dangers to which insect life is 

 exposed are manifold ; and therefore are the contrivances 

 for its preservation of the most perfect kind, and invariably 

 adapted to the peculiar habits of each tribe. The same 

 wisdom determines the food of every species of insect ; 

 and thus some are found to delight in the rose-tree, and 

 some in the oak. Had it been otherwise, the balance of 

 vegetable life would not have been preserved. It is for 

 this reason that the contrivances which an insect employs 

 for obtaining its food are curious, in proportion to the 

 natural difficulties of its structure. The ant-lion is car- 

 nivorous, but he has not the quickness of the spider, nor 

 can he spread a net over a large surface, and issue from his 

 citadel to seize a victim which he has caught in his out- 



