THE JUMPING BEAN 299 



cease to move, but can be roused again by renewed 

 warmth. 



How and why do these " beans," or, rather, fruit-seg- 

 ments (for they are not beans), move in this determined 

 purposeful manner? The whole proceeding has a mysteri- 

 ous and uncanny aspect. They have no legs, no spring ; 

 they are simple little smooth capsules, and yet they jump 

 and seemingly "walk" about. The explanation is that 

 there is a grub inside each so-called " bean." Cut one of 

 the beans or capsules open, and you find that it is a very 

 thin-walled and hollow case, but coiled on itself in the 

 cavity you open, and about half filling it, is a yellowish 

 white grub (Figs. 52 and 53). It is not a " maggot," but a 

 " caterpillar," that is to say, it is not legless, but has eight 

 pairs of legs namely, three pairs of short walking legs in 

 front, four pairs of sucker-like legs, and a hinder pair of 

 larger size called " claspers." It has a hard brown plate 

 on its head, and possesses hard jaws. It refuses to leave 

 the opened capsule, and crawls back again if forcibly 

 removed, and in the course of a few hours spins a silken 

 cover to replace the piece of " shell " you have cut away. 

 Mr. Rollo has lately succeeded in getting the caterpillar 

 to patch up its injured residence with a thin piece of 

 glass, such as is used by microscopists, which he put 

 in place of a side of the capsule removed by a knife. 

 He was thus able subsequently to watch through the 

 glass the movements of the little creature when it 

 causes the mended capsule or "bean" to jump. It 

 rears itself from the lower surface of the capsule, and 

 gives a series of sharp blows to the roof, projecting its 

 body with each blow, and thus overbalances the capsule, 

 or, if the flat side is lying downwards, jerks it along 

 much as one may sit with one's feet on the rail of a 

 chair and cause it to jerk along the floor by the swing- 

 ing movements of the body. The caterpillar does not 



