134 REVIEWS. 



ular case ; while the botanists to whom I refer do so on the ground 

 of analogous variations or transitions occurring in the same genus 

 or in the same family. For example, resting on the fact that Quer- 

 cxis Hex, Q. coccifera, Q. acutifolia, etc., have the leaves sometimes 

 entire and sometimes toothed upon the same branch, or present 

 transitions from one tree to another, I might readily have united 

 my Q. Tlapuxahuensis to Q. Sartorii of Liebmann, since these 

 two differ only in their entire or their toothed leaves. From the 

 fact that the length of the peduncle varies in Q. Rohur and many 

 other Oaks, I might have combined Q. Seemannll, Liebm., with 

 Q. salicifolia, N^e. I have not admitted these inductions, but have 

 demanded visible proof in each particular case. Many species are 

 thus left as provisional ; but in proceeding thus, the progress of the 

 science will be more regular, and the synonymy less dependent upon 

 the caprice or the theoretical opinions of each author." 



This is safe and to a certain degree judicious, no doubt, 

 as respects published species. Once admitted, they may stand 

 until they are put down by evidence, direct or circumstantial. 

 Surely a species may rightfully be condemned on good cir- 

 cumstantial evidence. But what course does De CandoUe 

 pursue in the case — of every-day occurrences to most work- 

 ing botanists having to elaborate collections from countries 

 not so well explored as Europe — when the forms in question, 

 or one of the two, are as yet unnamed ? Does he introduce 

 as a new species every form which he cannot connect by 

 ocular proof with a near relative, from which it differs only 

 in particulars which he sees are inconstant in better known 

 species of the same group ? We suppose not. But if so, 

 little improvement for the future upon the state of things 

 revealed in the following paragraph can be expected. 



" In the actual state of our knowledge, after having seen nearly 

 all the original specimens, and in some species as many as 200 rep- 

 resentatives from different localities, I estimate that, out of the 300 

 species of OujmlifercB which will be enumerated in the ' Prodromus.' 

 two thirds at least are provisional species. In general, when we 

 consider what a multitude of species were described from a single 

 specimen, or from the forms of a single locality, of a single country, 

 or are badly described, it is difficult to believe that above one third 

 of the actual species in botanical works will remain unchanged." 



