126 Journal of Travel and Natural History 



geographical areas. Thus it is ahnost impossible to cultivate 

 together, and to keep well marked, the species of Aquilegia, 

 Erodium, Antirrhinum, &c. This fact, joined to many others, 

 shews what minute precautions it is needful to take in making 

 experiments of this kind, to obtain truly incontrovertible results, 

 and how we must guard against concluding too hastily that we 

 know what passes in nature from that which we see in this way. 

 Not accepting, for my own part, the Darwinian hypothesis at all, 

 which is in disagreement with the intimate essence of organised 

 beings, and with the resistance we see them oppose to exterior 

 agents, I regard species, not as arbitrary conceptions of the 

 human mind, but as creations which have gone out at different 

 epochs under the powerful hand of God, which cannot change 

 one into the other, but which are often variable within limits 

 which are more or less extensive, which are sometimes difficult to 

 trace, but which exist always without possibility of being exceeded. 

 To seek those limits, I have proceeded by direct observation, by 

 studying species upon as many specimens as possible, by following 

 them in their different stations, and their geographical area, in 

 order to obtain a knowledge of the manner and degree of 

 variability, of the importance and the fixity of the characters in 

 each family or genus. When two or many forms have seemed to 

 me linked clearly by intermediates, I have regarded them as 

 forming part of the same species. Thus, in many places, plants 

 which I have proposed in my ' Diagnoses' as species, are described 

 here as varieties, because new material has shewn that there were 

 passages between them. On the other hand, I have not united, 

 and have described as distinct species the forms which up to the 

 present time have not shewn me any transitions, reserving myself 

 free to reduce if these are brought to light ; holding that it is less 

 harmful to eiT in separating than uniting ; the latter error being 

 less prominent, and, therefore, more difficult to correct, and pro- 

 ducing less harmful consecjuences, especially as regards geographical 

 botany." 



A single suggestion on a point of typographical arrangement, 

 and we will conclude. It would make the book much more easy 

 to use, if the names of the genera were printed at the head of 

 each page. As it is, the species are preceded only by the initial 

 letter of the genus, and one often has to turn over several i)ages 

 to ascertain what the initial letter means. J. G. Baker. 



