The microscope gave him the confirmation he expected by showing that all the different organs of the plant develop out of identical embryonic beginnings. In his absolute reliance on physical observation, however, he tried to go further than this and to detect in this way the reason why the plant does not always bring forth the same organ. He saw that the vegetative strength in the plant diminishes in proportion as its organism enters upon its later stages. He therefore attributed the differentiated evolution of plant organs from identical beginnings to an ever weaker process of development in them.