Owing to this process the plant, too, gains heights and develops new body parts. The growth of plants differs from that of animals since with plants not all parts of the body grow at the same time. He drew a clear line between mono- and dicotyledons after closely examining plant embryos. Names have not to be changed to avoid confusion and errors. Characteristics have to be exactly and distinctively defined which means that those basing on relative relations like heights are not to be used.
Characteristics have to be easily found by everybody.
Groups that are accepted by almost all botanists have to be kept. It has to be taken care that related plants will not be seperated, unnatural ones and those that are different are not to be united. Characteristics shall not without necessity be increased in number, but only as many shall be used as are necessary to make a reliable classification. Despite many positive first signs did he, too, still adhere to the separation of wooden plants and herbs. The problem of relation, the definitions of genera and families was also approached by a number of other botanists.