166 THE GRIBBLE 



moist earth to await their final transformation. Certain 

 beetles, however, have hit upon devices for avoiding 

 these constant trips to the surface with all their 

 attendant risks. Donacia crassipes is equipped with 

 two spines far back on the abdomen, with a little 

 spiracle or breathing hole at the root of each. The 

 organs of insects, be it observed, have a bewildering 

 knack of appearing in those parts of the person where 

 they are least expected, and there is nothing unusually 

 heterodox in carrying nostrils on the exterior of the 

 stomach. This insect frequents the roots of water- 

 lily and other succulent aquatics, knowing that such 

 roots contain spaces filled with atmospheric air. The 

 Donacia, while feeding, probes the roots with its spines, 

 tapping the air reservoirs, and breathing in their 

 contents through the spiracles. 



LXIV 



The Donacia only affords one out of ten thousand 



examples of marvellous adaptation of structure to the 



me wants of minute animals. Nobody can guess 



Gribbie j low manv a g es h ave rolled by since the 

 primeval Donacia was first supplied with spines, but 

 lately there has come to the knowledge of telegraphists 

 an instance of adaptation accomplished within less 

 than half a century. No material, perhaps, has in- 

 creased so enormously in importance to manufacture 

 in recent times as have indiarubber and guttapercha. 

 At no very distant time it was unknown in the 

 manufactured state; but, not to mention a thousand 



