26 NOVEMBER 1921, Page 26

Insect Transformation. By G. H. Carpenter. (Methuen. 12s. 6d. net.)—Professor

Carpenter's treatise is elaborate in design, well written and fully illustrated. He first deals generally

with form, growth and change, and then considers the three main types of insects, with open wing-growth, with hidden wing- growth, and those that are wingless. The chapter on the sur- roundings of growing insects contains much curious detail. Thus the sheep-maggot fly, that lays its eggs in the wool of live sheep, which are then bitten by the maggots, is extending its operations to the hills, and several species of Australian flies have developed this evil habit, presumably because large flocks of sheep are a new element in their environment.