474 ^y GARDEN. 



man to realize, but the multiplication of aphides affords a more 

 astounding illustration. A single aphis produces about ten every ten 

 days, and these again give birth to ten ; therefore to represent the 

 number of the progeny of one of these creatures for the space of 

 one year, thirty-six figures placed in a row would be required. As 

 the distance in miles beween the earth and the sun is represented 

 by only ten figures, and as seventeen figures would represent the 

 number of aphides required to form a line between the same bodies, 

 we may form a kind of indefinite vision of the immensity of the 

 power of multiplication possessed by aphides, and have a dim 

 idea of the rapid manner in which they can cover vegetation when 

 they appear. 



I have in my cabinet about 1 50 species, and I have traced a single 

 "species over sixty plants. Koch has given in his work 396 figures, 

 and Boisduval has noticed 163 species. Nevertheless there is con- 



FiG. 1043.— Aphis vastator, highly magnified. 



siderable confusion about many of the names. The one which I 

 named A. vas(aior •wa.s called by Curtis A. rapm, and both Mr. Curtis 

 and myself considered that it was the same species. By some 

 learned entomologists it was called, but I think wrongly, A. rumicis, 

 and now some consider that it is ^. dianthi. I have figured a drawing 

 of one of my own specimens from the "Year-book of Facts" of 1850 

 (fig. 1045), ^- dianthi in the larva state from a drawing kindly 

 made for me by Mr. Buckton (fig. 1046), and the A. rapce of Curtis 

 (fig. 1047 : No. S the winged insect. No. 7 the larva, and No. 8 natural 



