BICENTENARY OF LINN^US 31 



developed and strengthened in his hands as a result of his observations. 

 His dictum was species tot sunt diversce quot diversoB fornix ah initio sunt 

 creates. The resemblances between members of a single species were hence 

 held to be due to descent from an original pair, and the mutual infertility 

 of different species to be the natural penalty of the effort to traverse the gaps 

 established from the beginning. 



This view was somewhat modified in later editions of the Systema, in 

 which Linnaeus held that "all the species of one genus constituted at first 

 (that is at the Creation) one species, ab initio unam constituerint speciem; 

 they were subsequently multiplied by hybrid generation that is by inter- 

 crossing with other species." ^ 



The general relation of Linnaeus to his successors may be summarized 

 in a few words. The sixth epoch in the history of zoology extends from the 

 latter part of the eighteenth to the middle of the nineteenth century, and 

 may be called the Anatomical Epoch, because, through the labors of Cuvier 

 and his great English pupil and successor, Richard Owen, the taxonomic 

 studies of the Linnaean school vvcre supplemented by the establishment and 

 great development of the sciences of comparative anatomy and paleontol- 

 ogy. In spite, however, of the improvement and expansion of classification, 

 its bearing upon evolution was not generally perceived. Cuvier's researches 

 in these sciences further extended the dogma of the fixity of species; but 

 Owen, through his broader knowledge, gradually gave up the idea and 

 became an evolutionist, although not a selectionist. 



The seventh epoch, the Darwinian, in which happily we are living, has 

 seen the overthrow of the traditional doctrine of the fixity of species, and has 

 initiated the re-examination of all morphological phenomena in the light of 

 the doctrine of evolution. These morphological facts are reflected more 

 and more in our evolving classifications, which are the outgrowth of the 

 Linnaean system, and which now aim to express, not only degrees of homo- 

 logical resemblances and differences, but also (secondarily) degrees of genetic 

 kinship. 



The great " lawgiver of natural history " is thus seen in his proper per- 

 spective in a few at least of the series of historical antecedents and conse- 

 quents which intersected in him, inheriting, as he did on the one hand, the 

 language and general methods of the past and the doctrine of special 

 creation; inheriting on the other hand the new spirit and contributions of 

 Vesalius, Cesalpino, Ray and many others, and building upon this the 

 foundations of modern botany and zoology. 



* Osborn, H. F. From the Greelts to Darwin, p. 129. 



