Bentham and Hooker'' s Genera Plantaruni 57 



species slightly exceptional, without paying regard to the fact, that 

 if we separate their species, we must make not one, but four, five, 

 perhaps fifty analogous genera. In the works of floras, of gardens, 

 of descriptions of plants, of travellers, one does not see certain 

 transactions nor certain similarities. Monographers are after- 

 wards obliged to make a hecatomb of new genera as of new species. 

 Without doubt, there are great botanists endowed with much tact, 

 who divine the genera at the sight of a species, of a character, of a 

 particular habit; but these are exceptions. The rule is, that it is 

 necessary to have seen all the units, and to have studied them 

 well, in order to be able to group them suitably, and the merit of 

 the "Genera" of Messrs Bentham and Hooker, is that theyrest them- 

 selves on a review of species, not, it is true, so deep as those of 

 monographs, but nevertheless on a review, accompanied by analysis 

 and the comparison of numerous specimens. Let us ask from them 

 only that the reductions of genera be always well explained, and 

 the grounds fully exposed, so as to permit every one to make the 

 necessary verifications for himself. 



In this respect, Messrs Bentham and Hooker have taken pains. 

 Nevertheless, they might do still more, and in future inspire still 

 greater confidence. Let them not fear, with that object, to add a 

 few words from time to time. Let us cite an example : the 

 generic division of the Begoniaceee is almost the same as that 

 which we have admitted in the Prodromus. The fifty and odd 

 groups distinguished by Klotzsch on the old genus Begonia, and 

 of which he had made genera, are brought back with the title of 

 sections under the common name of Begonia, as we have ourselves 

 done. But Messrs Bentham and Hooker go a little further. They 

 abandon the genus Casparya, of Klotzsch, which we have cha- 

 racterized principally by a dehiscence of the capsule by means of a 

 longitudinal fissure of the angles or wings. Messrs Bentham and 

 Hooker say, in speaking of the whole family, " Capsulas dehis- 

 centiam in una eademque specie invenimus, nunc secus angulos 

 loculorum ut in Casparya, nunc secus faciem ut in Begonia." 

 If they had mentioned the species which presented that double 

 dehiscence, we might perhaps have been able to verify it, and on 

 a view of the facts, have ranked ourselves as of the opinion of our 

 friends. In doubt on the point, we have run over the whole genus 

 Begonia in our herbarium, without discovering a single example of 

 dehiscence anyAvhere but on the sides, to right and left of the 

 wings ; and it even appears to us impossible to have t\vo dehis- 



