AMERICAN SYCAMORES ARE POSSIBLY HYBRIDS 



AuKniFt 3, 1917. 



TO THE Editor of the Journal 

 OF Heredity: 

 I am much interested in the 

 articles on "Remarkable Button- 

 Balls" in your July issue, page 310. 

 The American buttonwood (Platanus 

 occidentalis), bears usually one fruit 

 ball, smooth on the outer surface, as 

 the styles break off. The introduced 

 tree, much planted in American cities 

 (just as it is in European towns and 

 cities), is Platanus acerifolia. The 

 London plane or maple-leaf plane has 

 two or three balls on each, string, which 

 are prickly to look at, as the styles 

 persist. The tree has never been found 

 in the wild state; and it is erroneously 

 called by nurserjonen "oriental plane" 

 in the United States, and "occidental 

 plane" in Europe. It is neither one 

 nor other; but it is intermediate be- 

 tween the two wild species. The true 

 oriental plane {Platanus orientalis) is 

 never planted in streets, either in 

 Europe or in the United States. It 

 has deeply cut leaves, and bears usually 

 six balls on each string; they are very 

 prickly. This tree is much less vigorous, 

 and is difficult to strike from cuttings, 

 while the London plane is struck from 

 cuttings very readily. 



The most remarkable fact is that re- 

 lated in the article on the button-ball 

 of the Morris Nursery Co. that the 

 (so called) "oriental plane" is the only 

 kind grown in their nursery, as it is 

 superior to the American species. Con- 

 sidering that the American Buttonwood 

 is the tallest, finest, and rnost vigorous 

 broad-leaf tree in forests of the United 

 States, will any one explain how it 

 degenerates when planted in American 

 towns? Will any one explain how the 

 native species is inferior to the i i- 

 ported one; and why the latter is pre- 

 ferred ? 



It is possible that the abnormal 

 specimens of P. occidentalis with three 

 or four balls to the string, may be 

 hybrids, as both P. occidentalis and P. 

 acerifolia are frequently planted near 

 each other in American cities. I should 

 be very pleased to see dried specimens 

 or branches with foliage and fruit-balls 

 attached from any tree of P. occidentalis 

 bearing an abnormal number of balls 

 to the string. Two balls have been 

 recorded frequently; but three or four 

 balls seem to be unknown in this species. 

 Yours truly, 



Augustine Henry. 

 Royal College of Science for Ireland, 



Dublin. 



The Relation between Race and Culture 



SOCIO-ANTHROPOMETRY, an inter- 

 racial critique. By B. L. Stevenson, Ph. D. Pp. 

 153. Boston, Richard G. Badger, 194 Boylston 

 Street, 1917. 



One school of sociologists thinks the 

 manners and customs of a people are 

 to be interpreted in terms of its racial 

 heredity. The Russian and German 

 civilizations, for example, differ because 

 the Russian people contain Mongol 

 blood which is not found in the limits 

 of the modern German empire. Dr. 

 Stevenson believes such a method of 

 study is not justified. She discusses the 

 culture of various European nations, 

 then describes their racial make-up, 



and points out in conclusion that corre- 

 spondences between the two are not 

 exact. Moreover, she declares that 

 the attempt to draw correspondences is 

 not legitimate, since the two studies, 

 anthropology and sociology, deal with 

 such different material in such different 

 ways. The question to which her book 

 is "devoted is an important one, and 

 although her contribution is not con- 

 clusive, it is well to have the matter 

 presented frequently. Numerous tables 

 w^hich she prints, giving anthropometric 

 data for the races of modern Europe, 

 will be found convenient for reference, 

 by students. 



553 



