IO Fl.. \slll. K, UTS ON NATI 



produced ready-made, without the necessity for 

 pacing through larval or infantile sta^->. Or 

 rather, they never grow up : they merely moult ; 

 and they produce more young while they are still 

 larvic. They are born fully formed, and proceed 

 forthwith to moor themselves, to feed, and to bud 

 out fresh generations, without sensible interval. In 

 No. 3 we have various stages in the development 

 of the spring brood. Above we see the pupa, or 

 chrysalis, produced from a grub (not very grub-like 

 in shape), which has sprung from an egg ; and on 

 the right, below, we see the shrivelled larval skin 

 from which it has just freed itself. This particular 

 aphis was thus born as a six-legged larva from an 

 autumn egg ; it passes through the intermediate 

 form of a pupa, or chrysalis ; and it will finally 

 develop into a winged "viviparous" female, such 

 as you see in No. 4 below, putting out its young 

 alive as fast as ever its wee body can bud them. 

 You may observe, however, that in the case of 

 aphides there is no great difference of form between 

 the three successive stages. Larva, pupa, and fly 

 are almost identical. 



In No. 4, again, we have a portrait from life of 

 such a winged female, the mother of a numerous 

 fatherless progeny ; for both winged and wingless 

 forms are produced through the summer. She is 

 round and well-fed, as becomes a matron. Observe 

 in particular the curious pair of tubes on the last 

 few rings of her back ; these are the organs for 

 secreting nectar or honey-dew, a point about which 



