THE GROWTH OF GROUPS 15 



Some biologists, however, do not regard characters 

 as perceptible things. Others, while admitting that 

 characters are perceptible, deny that they are units. In 

 the absence of a standard definition of the word unit, 

 it is difficult to discuss such a question. In a strict sense 

 there are no units in the organic world. At any rate, 

 I assume that living bodies contain these separate and 

 distinct attributes called characters. We may now 

 define the term group. 



A group is a number of individuals (more than one), 

 each possessing some particular character or characters 

 which are chosen arbitrarily as the distinguishing marks 

 of that group. 



OPINION AS TO CHARACTERS 



Since characters are to play a part in that which is 

 to follow, my conception of them must be described, 

 although it is somewhat uncertain. 



1. Every living body contains a large number of 

 distinct attributes or characters. The colour of a flower, 

 the brown pigment in the front layer of the human iris, 

 the beard of wheat, are characters in that they may be 

 present in or absent from the organism, apparently 

 without affecting the rest of the organism. 



2. As a rule characters appear to be superficial 

 in the constitution of the organism. They are small 

 details affecting the outward form or colour or small 

 peculiarities which may be observed in any of the 

 underlying parts, as for example in the skull of a verte- 

 brate animal (Fig. 6). They are also visible to us as 

 kinds of activity, such as we call instinct, habit, or beha- 

 viour. Certain of the more fundamental parts of the body 



