Genetical, morphological and embryological (gonads only) studies of intersexes [see B. A. 10(8): entry 17756] indicate that they start to develop as [female][female] and then from certain stage, known as the turning point, proceed to develop in a [male] direction. However, these intersexes differ morphologically from those of Lymantria and D. melanogaster by being essentially hermaphrodites because of the peculiarity in the development of those sexual organs whose imaginal discs had not become fully differentiated at the time of reversal. Such organs continue to develop as [female] organs, but along with them [male] organs appear presumably from fresh outpushings from the imaginal discs. The development of gonads is somewhat different. After the occurrence of the "turning point" [female] germinal cells in the ovaries are gradually transformed into [male]-like ones. The ovary itself is not transformed into a testis, except in very early reversals, but it buds out a testis-like organ, to which are confined some of the oocytes now transformed into spermatocyte like cells. The bearing of these studies on the sex determination in general, and in Drosophila in particular, is discussed.