Some points relating to the Morphology and Development of Sarcocystis tenella

Abstract

A short description is given of an important disease of sheep (Scrapie, Traber-krankheit, La Tremblante), believed to be caused by a heavy infection with Sarcocystis tenella, probably of increased virulence.The itchiness and paresis, the congenital transmission by the mother, the non-contagiousness, the long incubation period, etc., are readily explained on this view and a method of control of the disease based on this theory has been highly successful.The sarcocyst has been shown to be transmitted from sheep to sheep by intrauterine infection and by means of the milk.The minute structure of the sarcocyst is described and it has been shown in particular that the sickle-shaped spores are surrounded by a capsule. Under certain conditions, as in 1 per cent, glucose water and in the centre of the ripe cyst, these spores swell out and become globular, eventually bursting and scattering small chromatin granules. The further evolution of these granules is dealt with.The spread by means of milk and by the intestinal route is discussed¹.