The first generation is exemplified by arsenate of lead; the second, by DDT. Now insect hormones promise to provide insecticides that are not only more specific but also proof against the evolution of resistance...
The larva of an insect makes a hormone which keeps it from changing into a pupa until it has reached its full growth. Recent experiments with this substance have produced both dwarf and giant adult insects...
Although these small creatures use oxygen, they have no lungs. Each cell gets the gas from a private conduit, a fact that is not only interesting but also important to the welfare of man...
The phenomenon has long fascinated naturalists; now it sheds light on the forces that regulate growth and direct the specialization of cells
