174 



SCIENCE 



[N. S. Vol. XXXIII. No. 840 



America, and cultivated several kinds in Ger- 

 many. I will give an abstract of the changes 

 observed in one case, namely, with a tall kind 

 {Breit-korniger Mais, Zea altissima) brought 

 from the warmer parts of America. During the 

 first year the plants were twelve feet high, and a 

 few seeds were perfected; the lower seeds in the 

 ear Kept true to their proper form, but the upper 

 seeds became slightly changed. In the second 

 generation the plants were from nine to ten fe.'t 

 in height, and ripened their seed better; the 

 depression on the outer side of the seed had 

 almost disappeared, and the original beautiful 

 white color had become Quskier. Some of the 

 seeds had even become yellow, and in their now 

 rounded form they approached common European 

 maize. In the third generation nearly all resem- 

 blance to the original and very distinct American 

 parent-form was lost. In the sixth generation 

 this maize perfectly resembled a European va- 

 riety, described as the second sub-variety of the 

 fifth race. When Metzger published his book, 

 this variety was still cultivated near Heidelberg, 

 and could be distinguished from the common kind 

 only by a somewhat more vigorous growth. 



Bailey^" draws the following conclusion 

 in regard to American fruits and Ameri- 

 can climate : 



American fruits constantly tend to diverge 

 from the foreign types which were their parents, 

 and they are, as a rule, better adapted to our 

 environments than foreign varieties are. In less 

 than a century we have departed widely from the 

 imported varieties which gave us a start. At the 

 expiration of another century we should stand 

 upon a basis which is nearly if not wholly 

 American. 



Darwin" notes a similar case. 



Mr. Meehan has compared twenty-nine kinds 

 of American trees with their nearest European 

 allies, all grown in close proximity and under as 

 near as possible the same conditions. In the 

 American species he finds, with the rarest excep- 

 tions, that the leaves fall earlier in the season 

 and assume before their fall a brighter tint; that 

 they are less deeply toothed or serrated; that the 

 buds are smaller; that the trees are more diffuse 

 in growth and have fewer branchlets; and lastly, 



" " The Survival of the Unlike," 319, 1898. 

 "' " Animals and Plants under Domestication," 

 2d ed., 2, 27, 1890. 



that the seeds are smaller — all in comparison 

 with the corresponding European species. Now 

 considering that these corresponding trees belong 

 to different orders, and that they are adapted to 

 widely different stations, it can hardly he sup- 

 posed that their differences are of any special 

 service to them in the new and old worlds;" and, 

 if so, such differences can not have been gained 

 through natural selection, and must be attributed 

 to the long continued action of a different climate. 



As a matter of fact, most of these 

 changes are just what would be beneficial 

 in a country having a hot, dry, summer 

 with a relatively long winter. If planted 

 in a very moist place, the American elm 

 develops some of the characteristics of the 

 English elm. 



Woodruff^" has pointed out one marked 

 case of adaptation to climate. 



The shape and size of the nose and position of 

 the nostrils are now fairly well proved to be a 

 matter of selection of fittest variations. In the 

 tropics where the air is hot and therefore rarefied, 

 more of it is necessary and it is essential that 

 there should be no impediment to the air currents, 

 so that the nostrils are open and wide and the 

 nose very flat. Such a nose is unsuited for cold 

 countries, as it permits masses of cold air to 

 flood the air passages and irritate the lining 

 membrane, so that the nose must be large and 

 have much warming surface, and the nostrils 

 therefore are slender slits to admit the air in thin 

 ribbons easily warmed. The air being cold is 

 concentrated, and less of it is needed than in the 

 tropics and the slender nostril is no disadvantage. 

 The nasal index or extreme width of nose divided 

 by the extreme length, gradually increases as we 

 go to colder countries, where we find some races 

 with nose index much greater than one thousand, 

 i. e., width greater than length. It is now many 

 years since it was first pointed out that the open 

 tropical nostril was one reason for so much pul- 

 monary trouble of negroes out of tropics. Hence 

 there must have been a natural seleciion in cold 

 countries of one kind of variations — large con- 

 centrated noses, and a selection in hot countries 



■^ [The italics are mine. — W. D. B.] 



°' " Effects of Tropical Light on White Men," 4, 



