[Histochemical study of the subcommissural organ in chickens during development]

Some histochemical and particularly histoenzymological tests are performed on the subcommissural organ of chick embryos. A secretory activity appears about the 7th day. In 10 days old embryos and new hatched chicken the enzyme activities are of rather low intensity. Compared with the 10 days embryos, the newborn show some increase, but compared with the adult birds the activities remain weak. However the acid phosphatase activity is higher in the subcommissural organ than in the ependyma even in 10 days embryos.