224 Flashlights ox Natikk 



awakinj^ refreshed in April, come to the surface once 

 more, wliere they bej^in tlieir gyratory antics all over 

 aj^ain, da capo. It is a merry life ; and thouj^h 

 the whirligij^ can tiy, which he does occasionally, 

 'tis no wonder he prefers his skimming existence 

 on the still glassy sheet of his native waters. 



The two larger British water-beetles, which are 

 such favourite objects in the aquariums of young 

 naturalists, do not lead quite so exclusively aquatic 

 a life ; they pass their youth as larv.e in the pond, 

 and they return to it in their full-winged or beetle 

 stage, being most expert divers ; but they both 

 retire to dry land to undergo their metamorphosis 

 into a chrysalis, and they spend their time in the 

 pupa-case in a hollow in the ground. Something 

 similar occurs with many other aquatic animals, 

 which are thus conjectured to be the descendants^ 

 of terrestrial ancestors, whom the struggle for life 

 has forced to embrace the easier opening afforded 

 by the waters. 



In this respect, that rather rare and beautiful 

 little water-plant, the frogbit, shown in No. 9, 

 has a life-history not unlike the career of the 

 water-beetles. It is a quaint and pretty herb, 

 which never roots itself in the mud, like the curled 

 pond-weed, but floats freely about on the surface, 

 allowing its long roots to hang down like streamers 

 into the water beneath it. The short stem or stock 

 is submerged ; the leaves expand themselves freely 

 and loll on the surface. Like most other floating 

 water-leaves which thus support themselves on the 

 top of the water, they are almost circular in form 



