Nietzsche read William Rolph’s "Biologische Probleme" around mid-1884, and it clearly interested him, for his copy is heavily annotated. He made many notes concerning Rolph. Rolph was another evolutionary anti-Darwinist like Roux, who wished to argue for evolution by a different mechanism than natural selection. Rolph argued that all life seeks primarily to expand itself. Organisms fulfill this need through assimilation, trying to make as much of what is found around them into part of themselves, for example by seeking to increase intake and nutriment. Life forms are naturally insatiable in this way.