232 THE NATURAL UISTOr^Y EEYIEW. 



Tlie descriptive part of M. Jordan's work consists of 330 octavo 

 pages, and contains diagnoses of 352 species, all but two (poppies), 

 belonging to the families Eanunculaceae and Crnciferae. These 352 

 species are dismemberments of 58 Linnean t^^pes, so that on 

 an average there are as nearly as possible six Jordanian species to 

 each Linnean species. The extreme numbers are widely apart. 

 Braha verna is divided into 53 species, but in a great many cases the 

 Linnean species is divided into two only. The flora of France con- 

 tains at least four times as many species of Hanunculaceae and 

 Crnciferae, equal in value to the 58 here dismembered. We 

 are not, however, to understand that the others are monotypic 

 species. On the contrary, ]M. Jordan gives us clearly to understand 

 that when all the species are investigated by competent observers, 

 every one of them will be found to be coinposite, their apparent 

 unity being the consequence of the superficial manner in which they 

 have been looked at by botiinists. 



AVe cannot select a better illustration of the principles v.'hich guide 

 our author in his subdivisions than Draha (or Eropliila) verna, L. 

 The genus Erophila is said to contain about five species, but in Europe 

 it has hitherto been considered monotypic. The Asiatic species 

 are little known, and as they are similar in habit and aspect to our 

 common species, they will perhaps be found to be connected by a 

 gradual series of intermediates with E. verna. This common little 

 plant M. Jordan divides into 53 species, all but one (Corsican) 

 natives of the south of France. He recommends the careful study 

 of these forms to all observers, especially to those who are unwilling 

 to adopt his views in their entirety, with the most complete conviction 

 that no one can pay proper attention to them without at once be- 

 coming a convert. A little plant abundant every where, easily 

 cultivated froiu seed, taking up little space and growing readily on 

 any vvaste place, certainly offers every facility for observation. It 

 would be too much to expect it to vary in England exactly in the 

 same manner and to the same extent as in France ; but we need not 

 _ doubt that analogous variations will be met with, so that every one 

 has an opportunity of judging for himself of the value of the species 

 thus instituted. According to M. Jordan, they should be observed in 

 autumn, their distinctive characters being most evident in the young 

 leaves before they are injured by the winter frosts. The leaves 

 which accompany the flowering scapes are not characteristic either 

 in shape or colour. The points which it is most important to ob- 

 serve arc the simple or forked luiirs (on which cliaracter M'. Jordan 



