Peoblems of Gametic Constitution 73 



In this second section of this report I shall present such facts concerning the 

 behavior of different characters, and of the gametic agents productive thereof 

 as have a bearing upon the other portions of the investigation, and also some of 

 the data of the attempts to analyze the gametic constitution of my materials. 

 In this I have used simple characters of structure, color, and complex associa- 

 tions thereof, and simple reaction characters and complex associations thereof. 



The problems of heredity for the present, in experimental investigations, 

 center entirely about the methods of attack that arose from the rediscovery of 

 Mendel's work and as formulated in the present neo-Mendelian conceptions. 

 At the basis lies the idea of the individuality of manifestation and production 

 of " characters," and out of this has grown the misconception that the " char- 

 acters " are separate entities or individualized in the organism. It is distinctly 

 not true that the characters are so individualized, excepting in our recognition 

 of them as end-results or products of the operations of interacting antecedent 

 agents, and even in the observed product our methods of perception and 

 description tend to an excessive symbolic delimitation of them that is not 

 justified or representative of the truth. If it can be kept clearly in mind that 

 the characters in organisms are the same as in non-organized substances, the 

 resultant of the combining, interacting materials or factors of composition 

 and the conditions of the medium at the time of combination, no difficulty is 

 introduced into the problems of gametic constitution by the pragmatic indi- 

 vidualization of characters in plants and animals. 



With this conception of characters in organisms is associated the idea of tlie 

 antecedent gametic factors of composition whose interaction and presence in the 

 germinal material, the interactions and products of which must be provided for 

 by proper conditions in the medium. This idea of the factor or agent that 

 makes possible, and the determiner, the agent that of several possibilities 

 because of its presence decided the direction of the resultant reaction, are most 

 decidedly not " biological " conceptions, but are in all respects a purely physical 

 conception of the problem, and precisely the same as exist in non-organized sub- 

 stances. Neither factor or determiner nor any other agent is the carrier of 

 anything, any more than water of crystallization is the carrier of the crystalline 

 form or color or hardness. Determiners and factors need not even be sub- 

 stances, but may well be, in many instances, physical positions and relations in 

 the parts of the gametic substances. Many instances in non-organized sub- 

 stances could be cited where this single fact of configuration of the system was a 

 determiner of the action of the substance, and produced differences in the 

 reaction and in the products because of this initial difference of physical position 

 and arrangement of the parts of the system, and there is no a pi-iori reason why 

 the same may not be true of organisms. 



The fact of the segregation or distribution during gametic genesis of these 

 agents into different classes of gametes does most to disrupt cherished traditions, 

 and some of the conceptions and discussions that have been put forward by 

 neo-Mendelians, attempting to give a particulate shifting and sorting in the 

 gametes, is on the face of it absurd, and no better than Weismannism. In every 

 mating there are numerous contrasting pairs of equivalent characters, but why 

 some cross from one gametic system into the other, and others do not, and what 

 determines which shall undergo metathesis, is entirely unknown. In one series 

 6 



