442 X. GENERAL REMARKS. 



crude hj^othesis may appear supportable and to be 

 supported, while its proposer feels himself free to select 

 a small number of species in example of it, and to ignore 

 all the rest. It may so appear, because he naturally 

 selects in preference those which accord with his hypo- 

 thesis ; or (as in one late instance) deceptively culls out 

 those which can be so stated as to seem accordant with it. 



The more legitimate course for a truth-seeker, and the 

 one better calculated to lead to sound theories eventually, 

 is that of including all the species of a flora ; placing all 

 of them fairly under the same arrangements ; looking on 

 all alike under the same tests and aspects ; so that any 

 exceptions may become equally apparent as confirma- 

 tions ; opposing facts be shown as clearly and prominently 

 as the supporting facts. This would be the scrupulous 

 and philosophical course of proceeding ; — but it certainly 

 has not been the usual course with the framers of phyto- 

 geogi'aphical or phyto-geological hypotheses. There are 

 honorable exceptions, it is true ; and among the com- 

 mendable and reliable treatises, under this aspect, may be 

 melationed the writings of Professor C. Martins, — morally 

 so unlike those of a late Professor in London. 



And here, friendly reader, you may now find a reason 

 for the full lists of species and of orders, several times 

 repeated in this volume, under different an-angements. 

 Lengthy as it renders them, the completeness of the lists 

 is needed as a safeguard against the picking and culling 

 of facts in support of unsound hypotheses, and the 

 ignoring of those which might suggest a contradiction. 

 While the repetitions serve to place the same species or 

 orders under different aspects and combinations, ap- 

 -plicable to more various purposes than any single enu- 

 meration could possibly have adapted them for. 



