THE LOCAL DISTRIBUTION OF PLANTS. 677 



have sought to solve the problem how this remarkable adaptation lias 

 been brought about, instead of pausing to question the alleged law of 

 adaptation itself. And yet there have never been wanting numerous 

 and obvious facts, especially in the vegetable kingdom, which, if in- 

 terpreted at all, must be conceded to be incompatible with such a law, 

 at least unless materially modified and greatly enlarged. 



Mr. Thomas Meehan has remarked the fact that " almost all of 

 our swamp-trees grow much better when they are transferred to drier 

 places, provided the land is of fair quality. He referred, among others, 

 to sweet-bay, red maple, weeping-willow, etc., as within his own re- 

 peated observations growing better out of swamps than in them." 

 He further observes that " plants as a general rule, even those known 

 as water-plants, prefer to grow out of water, except those that grow 

 almost entirely beneath the surface." ' 



A great many facts are at hand to prove that those plants which 

 are found habitually growing in wet ground may be easily made to 

 grow in dry ground. The Iris versicolor (blue flag), which, in a state 

 of Nature, grows universally in marshes, and keeps perpetual com- 

 pany with Nuphar (pond-lily) and Sagittaria (arrow-head), is a com- 

 mon occupant of the driest gardens. The Lobelia cardinalis (cardinal- 

 flower), which I have found below tide-water mark, is also a common 

 garden-flower, and not difficult to cultivate. Almost as much may be 

 said for Lobelia syphilitica (great lobelia). The calla, the caladiums, 

 and the anthuriums, belong to this class, and the list might be in- 

 definitely extended. 



But differences of moisture in the soil are not the only ones which 

 are often overcome by natural or artificial changes in the conditions 

 of growth. Most of our prettiest wild-flowers which are found grow- 

 ing in deep, shaded glens in pure leaf-mould, have been captured by 

 florists, and made to thrive as well, and often better, under a cultiva- 

 tion which, with their most faithful efforts to imitate it, must be a 

 complete alteration of their native condition of life. Of such might 

 be mentioned at random the Trillium (wake-robin), the Cypripediwrn 

 (lady's-slipper), the Licentra (Dutchman's breeches), the Uvularia 

 (bell wort), the Erythronium (dog's-tooth violet), etc. 



So, too, plants growing under other conditions, as on hillsides, 

 and in open woods or meadows, as the violets, hepaticas, anemones, 

 and others, offer no difficulty to the florist. 



These are cases in which the transfer is from apparently more 

 favorable conditions to those less favorable. But similar results follow 

 from a reversal of this order. Plants may be successfully transferred 

 to ordinary garden-soil from localities which we would naturally sup- 

 pose to be less favorable to growth, but to which these seem to be 

 specially adapted. The columbine (Aguilegia), which grows on rocks, 

 often with scarcely any soil in which to root, or emerges from narrow 

 1 See Popular Science Monthly for May, 1874, p. 126. 



