Of True Bugs in General. 79 



damage as an order. The phylloxera, that nearly ruined 

 France's vines, and cost her far more than the indemnity 

 she paid to Germany for the Franco-Prussian war, is a 

 bug, a plant-louse. 



The powers of reproduction of plantrlice are simply 

 beyond the mind's ability to conceive. Huxley, rather 

 underestimating than overestimating the numbers of their 

 offspring, computed that the uninterrupted breeding of 

 ten generations from a single 

 ancestor would produce a 

 mass of organic matter equiv- 

 alent to the bulk of five 

 hundred million human be- 

 ings. Take all the people 

 living in the United States 

 and pile them in a heap. 

 Seven such heaps would not Fig I4 Winter eggs of the 



equal the progeny Of One hop-plant louse, and shriveled 

 i i A 11 ii i -i skin of the sexual female that 



plant-louse. All their biuk laid thern 



comes from vegetation, and 



the more the world conies under cultivation the greater 



the amount taken from garden stuff as compared with 



weeds and wild plants that have no economic value. That 



mound seven times as big as the population of the United 



States would represent nothing but stealings, waste. 



From a single ancestor, Huxley said. How can that 

 be ? \Yhy not a pair ? Because for generations there are 

 no fathers or brothers. 



Take for an example the hop-plant louse, that certainly 

 has done all in its power to ruin the hop industry. There 

 are generally plum trees to be found near hop-yards. On 

 these the aphids put in their time while waiting for the 

 hops to come up. An egg hatches out a wingless female. 

 In two or three days this stem-mother, so to speak, brings 



