Packard.] INSECTS of the plant house. 
Ill 
form of the true scale insects (Fig. 75, enlarged) that the 
female Mealy bug is but little more advanced in organization 
than these larvae, though greatly exceeding them in size. 
The male mealy bug (Coccus adonidum Linn.) is like the 
male scale insect (Fig. 76, enlarged), and still more nearly 
resembles that of the cochineal, which is two-winged, with 
two long caudal waxy threads. While the female Coccus 
undergoes no transformations, the male does, spinning a 
cocoon. Here we have a wonderful difference in form and 
Fig. TC. 
habits between the sexes, the female attaining the adult state 
by simple increase in size of the larval form, while the male 
passes thrpugh a well marked metamorphosis. This shows 
conclusively that metamorphosis' is an acquired mode of 
growth. The Coccus is a tenth of an inch long, covered with 
a white, cottony, mealy substance. The young are rather 
narrower than the old ones. The latter when about to lay 
its eggs, adheres by the long, slender beak to the surface 
of the leaf, and secretes from the abdomen a large cottony 
mass of fine particles of wax, which surrounds and partially 
15 
