24 FLASHLIGHTS ON NATURE 



crops are a species of aphis ; so are the " blight " 

 of apple-trees, the "fly" on turnips, and the most 

 familiar parasites of the hop, the cabbage, the pear, 

 and the potato. It is well for us, therefore, that the 

 aphides have roused against them so many natural 

 enemies among the birds and insects, or our crops 

 would be destroyed by their persistent efforts. The 

 ichneumon-flies alone kill their millions yearly; and 

 the lady-birds well deserve their popular esteem 

 for the good they do in keeping down the ever- 

 increasing numbers of these voracious insects. 



Yet, mischievous as they are, the tiny green 

 aphides are well deserving of study, both for their 

 personal beauty and their singular life -history. 

 Everybody can observe them, because they are 

 practically everywhere. If you have a garden, they 

 swarm on every bush. If you grow flowers in 

 your window, they live in every pot. If you con- 

 tent yourself with an occasional bunch of roses or 

 geraniums, you will find them, if you look, sucking 

 away contentedly on the leaves of the rosebuds. 

 Even in London parks or squares you may watch 

 the industrious ants creeping slowly up the stems 

 to milk their wee green cows ; you may see with 

 the naked eye, or still better with a pocket lens, the 

 grateful aphis exude a tiny drop of limpid honey 

 from its translucent tubes, and the ant lick it up 

 with unmistakable gusto. Go out into the parks or 

 gardens and examine it for yourself ; for every one 

 of the facts I have mentioned in this paper can be 

 verified with ease, if only you have patience. 



