1863.] NATIVE AND NATURALIZED BRITISH SPECIES. 559 



natives, and such as were introduced between the Roman domi- 

 nion and the discovery of America. 



The writers of the most ancient Floras were not so critical as 

 the moderns are ; and as the history, geography, and statistics 

 of the vegetable kingdom were less perfect two centuries ago 

 than they are at present, much stress cannot be safely laid upon 

 their authority. Besides, it cannot be safely assumed that our 

 older botanists observed all the plants that were existing in their 

 days. Like the older language of nations, the ancient language 

 of science was not very precise. Ancient British botanists did not 

 distinguish one hundred and forty species of Grasses, and about 

 ninety Sedges and other allied genera in the Order CijperacecR. 



Botanists do not lay much stress on the ancient names as aids 

 in establishing the nativity of species. It is a principle, like the 

 prehistoric one, which solves no difficulty. 



The third test, viz. the vicinity of houses, cultivation, sea- 

 ports, cannot be available, because these are the only localities 

 where most of these plants grow in all countries whatever. For 

 example. Borage, Melilot, Anchusa, and several Crucifers are 

 found in all countries to select such situations as they choose in 

 England. 



Spontaneous plants (not natives nor cultivated) are divided 

 into four classes by the greatest living authority on this subject, 

 viz. : — 1st. Aliens not yet established. 2nd. Species perfectly 

 naturalized, but their foreign origin known, and therefore un- 

 questioned; take Anacharis and Mimulus for examples. 3rd. 

 Perfectly naturalized, but their foreign origin only probable; 

 Aristolochia Clematitis and Narcissus biftorus are examples. 

 4th. Plants perfectly naturalized, but their foreign origin slightly 

 suspected ; examples. Narcissus Pseudo-Narcissus and Vinca 

 minor. 



There is a distinction between No. 1 and Nos. 2, 3, and 4 of 

 the above division, viz. between species imperfectly naturalized 

 and those completely established or perfectly naturalized. Also 

 there is a good line of demarcation between Anacharis and Mi- 

 mulus on the one hand — both introduced within historical memory 

 — and such plants as Narcissus, Periwinkle, etc., on the other. 

 All these might be classified either as certainly naturalized and 

 doubtful natives. But a question would still have to be answered. 

 What is the distinction between native plants and doubtful natives. 



