1. Moenkhaus, W. J.,Journ. Morphol. Vol. xxii. 1911, p. 23; Rawls,Biol. Bulletin, xxiv. 1913, p. 115. [Morgan,Science, Vol. xxxvi. p. 718, Nov. 22, 1912, has given an explanation of Miss Rawls’s results which is not inconsistent with sex determination by the spermatozoonin Drosophila. Note added March 5, 1913.]