The force exerted by Insects has long been remarked with surprise, and it is a fact familiar, not only to naturalists, but to all observant persons, that, making allowance for their small size, Insects are the most powerful of common animals. Popular books of natural history give striking and sometimes exaggerated accounts of the prodigious strength put forth by captive Insects in their efforts to escape. Thus we are told that the flea can draw 70 or 80 times its own weight.[87] The Cockchafer is said to be six times as strong as a horse, making allowance for size. A caterpillar of the Goat Moth, imprisoned beneath a bell-glass, weighing half a pound, which was loaded with a book weighing four pounds, nevertheless raised the glass and made its escape. [87] Haller. This and other examples are taken from Rennie’s Insect Transformations. This interesting subject has been investigated by Plateau,[88] who devised the following experiment. The Insect to be tested was confined within a narrow horizontal channel, which was laid with cloth. A thread attached to its body was passed over a light pulley, and fastened to a small pan, into which sand was poured until the Insect could no longer raise it. Some of the results are given in the following table:-- [88] Bull. Acad. Roy. de Belgique, 2^{e.} Sér., Tom. xx. (1865), and Tom. xxii. (1866). _Table of Relative Muscular Force of Insects (Plateau)._ Weight of body Ratio of weight lifted in grammes. to weight of body. Carabus auratus 0·703 17·4 Nebria brevicollis 0·046 25·3 Melolontha vulgaris 0·940 14·3 Anomala Frischii 0·153 24·3 Bombus terrestris 0·381 14·9 Apis mellifica 0·090 23·5 One obvious result is that within the class of Insects the relative muscular force (as commonly understood) is approximately in the inverse proportion of the weight--that is, the strength of the Insect is (by this mode of calculation) most conspicuous in the smaller species. In a later memoir[89] Plateau gives examples from different Vertebrate and Invertebrate animals, which lead to the same general conclusion. [89] Loc. cit. 3^{e.} Sér., Tom. vii. (1884). Authorities for the various estimates are cited in the original memoir. _Ratio of weight drawn to weight of body (Plateau)._ Horse ·5 to ·83 Man ·86 Crab 5·37 Insects 14·3 to 23·5