CHAPTER VII 



A NUMEROUS FAMILY 



PLANT-LOUSE, we will suppose, " resumed 

 Uncle Paul, "has just established itself on 

 the tender shoot of a rosebush. It is alone, all alone. 

 A few days after, young plant-lice surround it : they 

 are its sons. How many are there? Ten, twenty, 

 a hundred? Let us say ten. Is that enough to as- 

 sure the preservation of the species? Don't laugh 

 at my question. I know well that if the plant-lice 

 were missing from the rosebushes, the order of 

 things would not be sensibly changed." 



"The ants would be the most to be pitied, " said 

 Emile. 



"The round earth would continue to turn just the 

 same, even when the last plant-louse was dying on 

 its leaf; but it is not, in truth, an idle question to 

 ask if ten plant-lice suffice to preserve the race ; for 

 science has no higher object than the quest of provi- 

 dential means for maintaining everything in a just 

 measure of prosperity. 



"Well, ten plant-lice coming from one would be 

 far too many if we did not have to take account of 

 destructive agencies. One replacing one, the popu- 

 lation remains the same ; ten replacing one, in a short 

 tin 10 the number increases beyond all possible lim- 

 it-. Think of the dervish's grain of wheat doubled 



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