M. F. Plateau on the Muscular Force of Insects. 139 
XVI.—On the Muscular Force of Insects. 
By Fexix Piateau*. 
Tue measurement of the strength of invertebrate animals, and 
especially of Insects, appears never to have been the object 
of any investigations ; and yet, as will be seen hereafter, how 
much does this strength, compared with the weight of the 
animal, exceed that of Man and the Mammalia. Here and there 
only, in the writings of some authors, we find indications which 
prove that this extraordinary strength has not completely 
escaped observation. In this respect I shall cite two sentences 
of Phny. In the first place, speaking of insects im general, he 
says, “In his tam parvis atque tam nullis, que ratio, quanta 
vis, quam inextricabilis perfectio!” and again, with regard to 
the ants, “ac si quis comparet onera corporibus earum, fateatur 
nullis, portione vires esse majores.” Lastly, I find the follow- 
ing passage in one of Sir Walter Scott’s novels (Peveril of the 
Peak, chap. xxxv.) :—“ Hence the smallest creatures are fre- 
quently the strongest. Place a beetle under a tall candlestick, 
and the insect will move it by its efforts to get out ; which is, 
in point of comparative strength, as if one of us should shake 
his Majesty’s prison of Newgate by similar struggles.” 
What, relatively to the weight of the animal, is the muscular 
force in different species of insects ? how many grammes, on an 
average, can one of these species move by traction, or pushing, 
or during flight ? and is this force subject to any law? Such 
are the various questions that I have sought to solve by expe- 
riments, which are certainly very simple, but the results of 
which cannot but be interesting when compared with those 
furnished by researches of the same kind made upon the human 
subject and the horse. 
Before proceeding further, I will sum up in a few words the 
processes which I have employed. I ascertained the force of 
traction by making an insect draw horizontally a thread pass- 
ing over a pulley and having at its other extremity a pan con- 
taining weights, which are increased up to the maximum that 
the insect can move. 
Pushing is effected by burrowing insects on one of the extre- 
mities of a horizontal lever moving upon a vertical axis, the 
other extremity of which raises weights by means of a thread 
passing over a pulley as in the preceding case. 
Lastly, the force developed in flight is measured by attach- 
ing to the two posterior legs of the msect a small mass of wax, 
* Bullet. de Acad. de Belgique, 2me sér. tom. xx. Communicated by 
the author. 
