Hansen: Petalization in the Japanese Quince 



17 



Abundant nitrogen in the soil tends 

 toward leaf production among plants in 

 general . 



With an appreciation of these facts in 

 mind the question naturally arises : Did 

 stamens originate from petals or did 

 petals originate from stamens ? Neither 

 viewpoint can be satisfactorily and ade- 

 quately supported, although the evi- 

 dence leans most strongly to the view 

 that i petals originated from stamens. 

 This was accomplished probably by 

 the progressive petalization of the fila- 

 ments, accompanied by a proportionate 

 decrease in development of the anther 

 or zore-sac, until the anther disappeared 

 entirely. 



Although scientifically not fully under- 

 stood, petalization seems to be heritable, 

 since the phenomenon is frequently re- 

 peated by the offspring. Inheritance by 

 means of seed is possible when sufficient 

 stamen structure remains for pollination 

 purposes, and inheritance by vegetative 

 reproduction is frequently attained when 

 complete petalization robs the plant of 

 the chance to produce seed. Among 

 flowers of the composite type, repre- 

 sented by the asters and chrysanthe- 

 mums, doubling never prevents seed 

 production, due to the fact that petaliza- 

 tion is of a different morphological 



nature than the same phenomenon in the 

 groups lower than the composites. 

 Double petunias are propagated by seed 

 in a most interesting manner. The 

 hereditary character of the doubling is 

 so strong that seeds are saved from 

 petunias which are almost completely 

 petalized, only sufficient pistil and 

 stamen structure remaining to insure 

 pollination. 



Still another factor which may cause 

 petalization is disease due to the presence 

 of fungi and perhaps to other causes. 

 This type of petalization is not, of 

 course, hereditary, but may be infec- 

 tious. 



The phenomenon of the intergrading 

 of petals and stamens such as is here 

 illustrated is well known, but the fact 

 that it is so perfectly shown in the 

 Japanese quince is not a matter of com- 

 mon knowledge. No mention is made 

 of it in the botanical text-books now in 

 common use in which this interesting 

 subject is discussed, hence the matter is 

 brought to the attention of teachers and 

 others so that a source of unsuspected 

 illustrative material may thus be re- 

 vealed. Japanese quince is a common 

 ornamental, frequently used in land- 

 scape work. 



An Introduction to Social Psychology 



AN INTRODUCTION TO SOC[AI. PSY- 

 CHOLOGY, by Charles A. Ellwood, Ph.D., 

 professor of sociology in the University of 

 Missouri. Pp. .343, price $2.00 net. New 

 York, D. Appleton & Co., 1917. 



Eugenics is outside the scope of Pro- 

 fessor EUwood's book, and he does not 

 even refer to it directly. But what he 

 has to say about evolution and human 

 nature are of interest to the student of 

 heredity, even though his discussion is 

 largely theoretical and little illustrated 

 by concrete examples. Four wide- 

 spread views of human nature must 

 now be abandoned, he says. These 

 are (1) the view that the individual is 

 passive and acts only as the result of 

 stimuli from the environment; (2) 

 that the individual's acts are due to 



the desire to seek pleasure or to avoid 

 pain; (3) that the individual is in- 

 nately selfish, and such altruism as 

 exists is an out-growth of egoism; (4) 

 that the individual is a self-contained 

 entity. Instead, "science shows the 

 individual to be a self-activ^e unit, 

 fashioned by the forces of an organic 

 evolution which has been, at the same 

 time, a social evolution; that is, the 

 individual has been developed as a 

 member of a group, and the environ- 

 ment to which he has had to adapt him- 

 self has been largely an environment of 

 his fellow beings." Action really 

 springs from within, although it is 

 guided by the external environment; 

 and altruism is jurt as original a tend- 

 ency in haman nature as is selfishness. 



