20 Flashlights ox Nati'kk 



males arc bucldccl out ; it is only when the cold 

 threatens to destrov the entire eolonv that little 

 husbands are born, so as to ^ive rise to ej^s^s which 

 may bridge over the ^ult between sunrner and 

 summer. If you keep the insects warm, however, 

 and supply them with abundant food (as in a con- 

 servatory), they will J40 on producins^ imperfect 

 females and fatherless broods, without intermission, 

 for many years together. The ej^j^-laying genera- 

 tion is thus shown to be merely a device for meeting 

 the adverse chances of winter ; the budding process 

 suffices well enough, as long as warmth and food 

 render the possibility of freezing or starvatii)n un- 

 important. 



On the other hand, the eggs and the brood born 

 from them revert to the earlier habit of the race, 

 when it was still an active, free-flving type, before 

 it had been demoralised by acquiring its sedentary, 

 parasitic habits. They hatch out into active little six- 

 footed or six-legged larv;e, which again, in somecases, 

 give rise to very similar chrysalis fv)rms, and finally 

 develop into the "viviparous" or budding females. 

 Whenever a species earns its livelihood with too 

 little exertion, it invariably degenerates, and often 

 grows small, unintelligent, and vastly prolilic ; for 

 superior races have relatively small families, while 

 inferioi races reproduce by the million. The mites 

 which inf(.'st cheese and other fo(xl-stuffs are an 

 exactly analogous case to that of the aphides, for 

 they are degenerate spiders, grown small and prolific 

 tlirough the excessive ease of life afforded them by 



