On the germination of the seed of the castor-oil plant ( Ricinus communis )

Abstract

The germination of those seeds in which the non-nitrogenous reserve material is found to be an oil and not a carbohydrate was first studied by Sachs, who, in a series of papers published in 1859, put forward a hypothesis to explain the manner in which the oil becomes available for the nutrition of the young plant. He records as his starting point the observation that at the onset of germination the oil gradually disappears, just as starch disappears from the reservoirs when germination is started in a seed containing it, and he shows that the development of the young plant proceeds concurrently with this disappearance. From this it follows that the oil, like the starch, is a reserve material to be made use of by the embryo in its early growth. So far as he deals with the changes taking place in the oil, he puts forward the view that starch is directly formed from it, and that this conversion is the first step that may be traced. Subsequently, sugar arises from the starch, and thus, in all seeds alike, the non-nitrogenous reserves travel as sugar from their storehouses to the seat of growth.