388 NATURE'S TEACHINGS. 



of the Skip -jack. The end of this tongue fits into a groove in 

 the " sternum." 



When the beetle falls on its back, it curves its body as shown 

 in the illustration, the tongue thus being freed from its groove. 

 It then smartly springs the tongue back into its place with the 

 sharp clicking sound already referred to, and does so with 

 such force that it leaps into the air to some height. 



Generally it falls on its feet, but if it should fail, it repeats 

 the process. If one of these beetles be laid on a plate or 

 similar smooth surface, it will skip ten or twelve times without 

 stopping, and after a short rest will begin again. 



THERE are some curious little beings, popularly called 

 Spring-tails, which afford excellent examples of the Leaping 

 Spring. Their exapt place in the system of Nature is rather 

 uncertain, some zoologists considering them as insects, while 

 strict entomologists reject them. They are very small, and 

 mostly of a darkish brown colour. 



Plenty of them may be found under stones in damp spots, 

 under bark, and in similar localities, though they are often 

 found in houses, and have frequently traversed the paper on 

 which I have been writing this book. Cellars are favourite 

 localities of theirs, and a little flour sprinkled on a plate or 

 piece of paper in a cellar is tolerably sure to attract them. 

 Although they are certainly not more than the fifteenth of an 

 mch in length, they may be at once recognised by their 

 peculiar attitude, which very much resembles that of a dog or 

 cat in its usual sitting posture. 



As long as they are not disturbed they crawl about in a 

 quiet manner, but if touched, or even alarmed, they suddenly 

 make a tremendous leap, propelling themselves by means of a 

 forked and elastic tail, doubled under their bodies, and acting 

 just like the tongue of a Skip- jack. 



BELOW the Skip-jack Beetle is shown the common Grass- 

 hopper, as an example of muscular leaping springs. 



We all know what wonderful leaps the Grasshopper, Cricket, 

 and all their kin can make, the leaping movement being 

 evidently intended more as a means Of defence than as an 

 ordinary mode of locomotion. The same may be observed in 



