Haploidy in the Male Sawfly (Tenthredinidae) and some Considerations arising therefrom

Abstract

IN 1907 Doncaster published certain statements on the gametogenesis of the common gooseberry sawfly, Nematus ribesii Scop. (“Gametogenesis and Fertilisation in Nematus ribesii”, Quart. Journ. Micro. Sci., vol. 51 n.s., 1907), but later, in 1909, he published a correction (ibid. 1909. “Gametogenesis of the Sawfly Nematus ribesii. A Correction.” NATURE, Dec. 2, 1909, p. 127). Unfortunately, he never resumed the investigation, and the problem was so left that its solution demanded work ab initio. Since then, nothing further has been done to elucidate the question, but work done by me on the spermatogenesis of the sawfly Pteronidea melanaspis Htg., together with certain breeding experiments with Pteronidea (Nematus) ribesii, permits certain pronouncements which throw considerable light on the subject.