He also observed that gymnosperm ovules were not enclosed in an ovary wall, leading to the establishment of one of the basic differences between angiosperms and gymnosperms.

• 他还观察到裸子植物的胚珠并不是被子房壁包围，这个发现直接导致了被子植物和裸子植物之间最根本的几点区别的建立。