556 KEroEi — 1884. 



trasted with that of Europe : perhaps also to touch upon the causes or 

 anterior conditions to which much of the actual differences between the 

 two floras may be ascribed. For, indeed, however interesting or curious 

 the facts of the case may be in themselves, they become far more instruc- 

 tive when we attain to some clear conception of the dependent relation 

 of the present vegetation to a preceding state of things, out of which it 

 has come. 



As to the Atlantic border on which we stand, probably the first im- 

 pression made upon the botanist or other observer coming from Great 

 Britain to New England or Canadian shores, will be the similarity of 

 what he here finds with what he left behind. Among the trees the white 

 birch and the chestnut will be identified, if not as exactly the same, yet 

 with only slight differences — differences which may be said to be no more 

 essential or profound than those in accent and intonation between the 

 British speech and that of the ' Americans.' The differences between 

 the beeches and larches of the two countries are a little more accentuated ; 

 and still more those of the hornbeams, elms, and the nearest resembling 

 oaks. And so of several other trees. Only as you proceed westward 

 and southward will the differences overpower the similarities, which still 

 are met with. 



In the fields and along open roadsides the likeness seems to be greater. 

 But much of this likeness is the unconscious work of man, rather than of 

 Nature, the reason of which is not far to seek. This was a region 

 of forest, upon which the aborigines, although they here and there 

 opened patches of land for cultivation, had made no permanent encroach- 

 ment. Not very much of the herbaceous or other low undergrowth of 

 this forest could bear exposure to the fervid summer's sun ; and the 

 change was too abrupt for adaptive modification. The plains and prairies 

 of the great Mississippi Valley were then too remote for their vegetation 

 to compete for the vacancy which was made here when forest was changed 

 to grain-fields and then to meadow and pasture. And so the vacancy 

 came to be filled in a notable measure by agrestial plants from Europe, 

 the seeds of which came in seed-grain, in the coats and fleece and in the 

 imported fodder of cattle and sheep, and in the various but not always 

 apparent ways in which agricultural and commercial people unwittingly 

 convey the plants and animals of one country to another. So, while an 

 agricultural people displaced the aborigines which the forests sheltered 

 and nourished, the herbs, purposely or accidentally brought with them, 

 took possession of the clearings, and prevailed more or less over the 

 native and rightful heirs to the soil, — not enough to supplant them, 

 indeed, but enough to impart a certain adventitious Old World aspect to 

 the fields and other open grounds, as well as to the precincts of habita- 

 tions. In spring-time you would have seen the fields of this district 

 yellow with European buttercups and dandelions, then whitened with 

 the ox-oye daisy, and at midsummer brightened by the cerulean blue of 

 chicory. I can hardly name any native herbs which in the fields and at 

 the season can vie with these intruders in floral show. The common 

 barberry of the Old World is an early denizen of New England. The tall 

 mullein, of a wholly alien race, shoots up in every pasture and new clear- 

 ing, accompanied by the common thistle, while another imported thistle, 

 called in the States ' the Canada thistle,' has become a veritable 

 nuisance, at which much legislation has been levelled in vain. 



According to tradition the wayside plantain was called by the 



