623 



THE MICROSCOPE. 



distance, in comparison with its size. The body is 

 covered with numerous minute scales, mostly of a beau- 

 tiful silvery or pearly lustre, and curiously striated. 



Podura plumbea, Lead-colour Springtails, are generally 

 found in damp places, leaping about like fleas. They 



prefer a moist atmosphere, 

 some take to the surface 

 of the water in secluded 

 places ; their food seems 

 to be vegetable matter of 

 any kind in a stage of 



Fig. 286.— Podura plumbea. (Inthe small decay; the little active 



circle the insect appears life-size.) creatures are seen to leap 

 about if a stone in a damp situation in the garden is 

 turned up, or if a dark, damp corner of the cellar, about 

 the beer-barrel, is searched ; or if we peep among the 

 roots of the ferns in the fern-case. Poduridas, varying in 

 form, colour, &c. are produced from eggs, undergo no 

 metamorphosis, are not parasitic, have from twelve to 

 sixteen simple eyes ; are furnished with strong mandibles, 

 and a broad, curious- looking snout, and a rather long 

 body, terminating in a bifid tail, which by alternately ex- 

 j3anding and contracting, enables them to leap great dis- 

 tances. The antennae are very long, and covered with 

 scales and fine hairs. To obtain the scales from the body 

 without damage — which is certain to occur if the Podura 

 is touched by the fingers — take a small test-tube and 

 quickly place it over the insect, when it instantly springs 

 up and clings to the side of the tube ; insert a thin glass- 

 cover beneath, and close up the open end. One drop of 

 chloroform carefully administered instantly kills the in- 

 sect ; in a very short time this evaporates and leaves the 

 tube quite dry. By gently shaking the tube a number of 

 scales will drop off and adhere to the thin glass cover ; 

 remove this, and make it secure to the ordinary glass-slip. 



Mr. E. Beck says, "that the best scales are obtained 

 from insects found in comj)aratively dry places." Mr. 

 S. J. Mclntire, in an interesting paper on the Podura, 1 

 confirms this statement, but believes that the "test-scale" 

 Dgured by Mr. Beck belongs to a distinct species. The 



(1) Science Gossip, March, 1SC7. 



