Note 32 — PART I.—MORPHOLOGY AND PHYSIOLOGY (continued 3)

Pancritius, who also adopted Müller’s views, lays much stress on the fact that in larvæ of some orders the tracheæ do not enter the rudimentary wings until the end of larval life, and hence the wings have not originated from tracheal gills, but were originally “perhaps only protective covers for the body.”