THE COMMON FLEA 269 



an American entomologist, who once visited an exhibition 

 of performing fleas with the view of determining to what 

 extent the performances were really the result of train- 

 ing, and how far, therefore, they indicated any docility 

 in the performers, came to the conclusion that all the 

 movements consisted of struggles on the part of the in- 

 sects to escape, and that what looked like concerted action, 

 in which, of course, the greatest amount of intelligence 

 seemed to be exhibited, could be accounted for in other 

 and more natural ways. Take, for example, the waltzing, 

 in which the fleas go spinning round in pairs to the 

 sound of a musical box. Two fleas of equal size and 

 strength are attached to an extremely delicate piece of 

 wire, one at each end ; but as they are fastened in such 

 a way as to face in opposite directions and at right 

 angles to the wire, their struggles produce equal and 

 opposite pulls at the end of the bar, or, in other words, 

 form what in the language of mechanics would be termed 

 a "couple," and therefore necessarily produce, without 

 any intention on their part, a rotary motion. To aid in 

 the illusion, a small orchestra is added, consisting of 

 fleas fastened before tiny models of musical instruments. 

 As they are set upright, their legs can only flourish 

 about in the air, suggesting the idea of their performing 

 on the instruments ; and if they should be at all slow to 

 begin their "pa wings," an attendant stirs them up by 

 running a little barb from a feather across their legs, 

 when, of course, they set to work kicking about vigo- 

 rously. In the duelling performance we have something 

 very similar to the orchestra : two fleas are fastened up- 

 right to little wire pillars, and tiny wands in lieu of 

 swords attached to their fore-legs; they are placed 

 opposite one another, but at such a distance that they 

 are just out of one another's reach, except with the 



