380 TRANSFORMATIONS OF INSECTS. 
them. Now in the spring these eggs are hatched, but they do 
not produce caterpillars or grubs, but imperfect Aphzde, which 
have no wings, and which are all females. So far as is known, 
all the males die in the autumn, and the females also as soon 
as they have laid their eggs, so that in the early spring there 
are no other Apffid@ in the world except these imperfect females. 
Now these, as everybody knows, are the mothers of millions and 
millions of plant lice, which are exactly like them —that is to 
say, imperfect because they are wingless. These children are pro- 
duced time after time, each set giving birth to others, and sometimes 
there are nine or ten successive generations. The last generation 
' THE ROSE Aphis. 
of Aphide does not produce those like unto itself, but perfect 
male and female individuals with wings. All the generations of 
imperfect females are not born from eggs, but they are born 
alive, and they may be traced with the microscope like little 
buds within the old ones. Bonnet, Réaumur, Owen, Huxley, 
Carus, Leydig, and Balbiani especially have studied these interest- 
ing insects. As soon as they are hatched the imperfect females 
begin to grow and increase in size, and they attain their full 
dimensions in ten or twelve days ; and then these curious little inside 
buds are born at the rate of three, four, or seven a day. When 
they are born they are miniatures of their mother, and in ten 
days they begin to produce others. The second generation does 
