The Cows that Ants Milk 



aphides did not always lead so slothful a life : 

 they are creatures with a past, the unworthy 

 descendants of hij^hcr insects, which have de- 

 Ljenerated to this level 

 through the excessive 

 abundance of their food, 

 and through their adop- 

 tion of what is prac- 

 tically a parasitic habit. 

 When life is too easy, 

 men and insects in- 

 variably degenerate : 

 struggle is good for us. 

 One of these little indi- 

 cations of a higher past 

 Mr. Knock has given us 

 in the upper part of 

 sketch No. 3. For some 

 members of the brood 

 go through regular stages 

 of grub and chrysalis, 

 like any other flies ; or, if 

 you wish to be accurately 

 scientific, pass thnjugh 

 the usual forms of larva 

 and pupa, before they 

 reach the full adult con- 

 dition. This, of course, shows them to be the 

 descendants of higher insects which underwent the 

 common metamorphosis of their kind. But most 

 of the budded-out, fatherless broods in summer are 



NO. 3. — BUDDING MOTHKR — 

 I'RODUCINc; A KATHERLESS 

 HROOD 



