dogma generally accepted till the appearance of the theory of descent, we should be justified in demanding proof; but since dogmas as a rule do not admit of proof, Linnaeus simply states his view[32], unless we are to take the sentence, ‘negat generatio continuata, propagatio, observationes quotidianae, cotyledones,’ as proving the assertion that new species never appear. We shall see further on to what surprising conclusions Linnaeus was himself led by his dogma, when he had to take into account the relations of affinity in genera and larger groups. The species and the genus, he continues, are always the work of nature, the variety is often that of cultivation; the class and the order depend both on nature and on art, which must mean that the larger groups of the vegetable kingdom have not the same objective reality as the species and the genus, but rest partly on opinion. That Linnaeus estimated the labours of the systematists after Cesalpino and the contributions of the German fathers of botany up to Bauhin, as they have been judged of in the present work, is shown by paragraph 163, where he explains the word habit, and adds that Kaspar Bauhin and the older writers had excellently divined (divinarunt) the affinities of plants from their habit, and even real systematists had often erred, where the habit pointed out to them the right way. But he says that the natural arrangement, which is the ultimate aim of botany, is founded, as the moderns have discovered, on the fructification, though even this will not determine all the classes. It is interesting therefore to observe how Linnaeus further on (paragraph 168) directs, that in forming genera, though they must rest on the fructification, yet it is needful to attend to the habit also, lest an incorrect genus should be established on some insignificant mark (levi de causâ): but this attention to the habit must be managed with reserve, so as not to disturb the scientific diagnosis.