Peoblems and Concepts of Evolution 7 



(3) Complex redistributions, of which two grades have been present in my 

 materials: (a) Double decomposition: Metathesis (the Mendelian reaction), 

 in which there is in the reaction incident to the reproductive process, decom- 

 position of each of the gametic systems present in respect to essentially 

 equivalent and mutually replaceable groups, which then interchange places in 

 the gametic systems of the two gametically different races present in the reac- 

 tion, (b) Internal rearrangements, in which there is dissociation of the agents 

 present in the gametic system, with rearrangements of them into new relation- 

 ships, with the end-result that there appears in the resulting individual product 

 either new or changed aspects of the character or characters. 



ATTRIBUTES. 



Attributes, which are characters distinguishing bodies as size, stature, weight, 

 and the many other characters that serve to distinguish one individual mass 

 from another, or one individual organism from another of the same species, 

 are in the main those characters in the organism that have been in the past 

 chosen for the operations of the " selection process," and for the diverse attempts 

 to alter " quantitatively " the nature of the individual. The differences that 

 fall in the category of " fluctuating variations " belong properly to this class of 

 characteristics, and in the non-living as in the living are in their manifestation 

 much influenced by the conditions of the medium. 



In organisms there seems to be a basis of permanent differences in the 

 capacity of these attributes to be manifested. Thus, in stature or in weight 

 (beans) there are values in the population that seem to be limits beyond which 

 change is not possible, and also in some instances values that may be maintained 

 in pure lines without change. What this signifies is difficult to decide, but the 

 investigations of Johannsen, Jennings, and others have at least made a decided 

 step in the solution of the problem. No doubt in final analysis it, too, is the 

 product of the relations of the factors that are productive of the specific 

 properties of the individual, and may be due to many causes in so complex a 

 system as organisms are. In some of the later chapters detailed experiments 

 in this direction show how, in some instances at least, the conditions present are 

 to be explained. It is not to be expected, however, that upon the basis of this 

 conception any alteration of the nature of the substance can be produced by the 

 accentuation of these attributes, because there is no point of entry for any 

 operation that could possibly be productive of any type of change in the specific 

 properties, and because throughout the factors productive of them are main- 

 tained in the system in their original relations, and no means is present in the 

 attempt to alter the attributes, whereby a change in the relations or in the 

 factors that are present could result. This is, in my experiments, the reason 

 for the failure of " fluctuations " to carry alteration beyond a certain limit by 

 any means. It is not due to the inefficiency of " fluctuations " and the efficiency 

 of " mutations," but to the fact that in the " fluctuations " only the differences 

 in attributes have been concerned, and in the operations based thereon there 

 has been no method present that was able in any way to change the nature or 

 relations of the specific properties present. 



