58 n. PERMANENCE OF SPECIES. 



But does NatuPvE warrant tliese changes of species ? 

 Granting the non-existence of distinct lines of demarca- 

 tion between ordinal or generic groups, it is still not a 

 necessary inference that the analogy ought to be extended 

 to species. Notwithstanding the discordant views of bo- 

 tanical writers, it may still be, that natural species are 

 really not groups of individuals thus mutually convertible, 

 or without any positive limits between them. A species 

 may be something in nature far more strictly individual 

 and distinct than a genus or an order. All its constituents 

 or rej)resentatives may possibly have sprung from a single 

 and distinct origin in each case, continued either by direct 

 partition or by reproduction (which is only another mode 

 of iDartition.) And that origin may not ever have been a 

 preceding and different species. And as the present spe- 

 cies shall run out their allotted duration, and disappear 

 from the earth in their turn, it seems quite possible that 

 none of them will thus disaj)pear by (or after) giving ori- 

 gin to some succeeding and different species. The prac- 

 tical question now comes by inquiry, how far does our 

 actual knowledge avail us towards establishing any such 

 individual distinctness of species, — present, past, future ? 



Actual knowledge goes a very small way towards settling 

 the mooted question ; although we do certainly construe 

 the ascertained facts of nature as being, on the whole, ad- 

 verse to the doctrine of a gradual mutation of species, 

 and favorable to that of their permanent distinctness. 

 Reference may again be made to the ' Geographic Bo- 

 tanique/ pages 1066 — 1126, for a full general exposition 

 of facts and opinions bearing upon this and kindred ques- 

 tions. But in making this reference, it may be useful 

 again to remind readers, that the Author of the ' Geo- 

 graphie Botanique ' is a greater proficient in comparing 

 and generalizing facts, than he is in the art af inductive 



