132 Controversial Questions. 



characters ''acquired" which can be traced to some effect 

 of the environment on the organism in question.^ 



Acquired characters, as the term is understood in 

 Zoology and Anthropology, are parallel to the so-called 

 nutritional modifications of the botanist. 



Let us compare the two groups of phenomena. 



We often find in the literature of this subject a dis- 

 tinction drawn between the so-called nutritional char- 

 acters and individual variations. The former are said 

 not to be heritable and therefore not to provide material 

 for selection. But the latter are assumed to be due to 

 unknown causes, and to be heritable and fixable by selec- 

 tion. 



The phenomena of nutritional modifications are 

 equally well known in agriculture and in horticulture. 

 The edges of the field and the spots in it which have re- 

 ceived an undue share of manure give rise to luxuriant 

 plants. On the other hand the weed that germinates in 

 mid-summer is often of shrunken stature and after pro- 

 ducing a few leaves, blooms and sets seed. In the gar- 

 den too, plants w^hich are grown in dry places or in poor 

 soil or which come up late are often miserable specimens. 

 We often see beside richly branched Datura, beside Ama- 

 r ant us a meter high, beside normal buckwheat or a poppy 

 covered with blossoms, single specimens often only a 

 decimeter high, almost or quite unbranched, with small 

 and few flowers which nevertheless are able to set seed 

 though these may be few in number. 



If we seek for the grounds on which the distinction 

 so often drawn between nutritional modifications and in- 



^ Other types of definition, especially those which involve the 

 question as to whether the variations arise in the germ or not lead 

 to much confusion. See Intraccllulare Pangenesis, p. 206, and Kriiid- 

 kundig Jaarhoek, Vol. I, 1889, p. 152. 



