Analysis of Heterogeneity in the Population 337 



It is shown that the systems investigated and their component elements, the 

 simplest characters, are the product of gametic agents in the composition of the 

 organic system; that they are specific in position, relations, and in result. It 

 further is evident that the same agent may at different times and in different 

 systems sustain different relations; hence the diversity of the arrangements 

 presented between the elements of the pattern-system, an array that in many 

 respects reminds one of the series presented in many complex inorganic series 

 where the same members are present, but in differing arrangements. It is 

 shown that the system, although complex and the product of many interacting 

 agents, nevertheless acts as a unit in many reactions, passing through the opera- 

 tions of reproduction and crossing in its entirety, or at other times emerging 

 from the reactions changed in relations and arrangements of the elemental 

 simplest characters, indicating altered relations between the conditioning 

 agents. All of this complexity of arrangement and operation is completely 

 submerged by any attempt to treat the conditions in the pattern in the usual 

 quantitative biometric manner. 



Thus far in the analysis of the conditions found in a complex array in nature, 

 I have found out some of the things that were there and some of the agents that 

 are productive of the heterogeneity in the system investigated. There appears 

 no evidence for the distinction between quantitative and qualitative that has 

 been drawn by De Vries and Weismann, and the position and role or even the 

 existence of the much discussed and abused fluctuation must be questioned and 

 demonstration demanded, and the causes actually determined in a more certain 

 manner, before it is accepted as a constantly present feature of the phenomena 

 of pure lines. 



It is clear that it is possible to divide a population into different, homozy- 

 gous-acting, well-defined biotypic groups that are pragmatic divisions and as 

 such they are in the arrangement of a system, which remain permanent so long 

 as the structure of the system is not disarranged. Within some of these 

 further separations are possible into finer groups, but how many or how far 

 this could be carried is not shown. 



In successive generations in the same place and in different places it is clear 

 that there is heterogeneity, that it is delimited and shows in the main deter- 

 minate response to the total set of conditions, internal and external, that the 

 organism has to meet. It is shown as the result of some of the tests in which 

 populations were transplanted from the different colonies to like conditions in 

 nature or in the laboratory, that the gametic composition of the original colony 

 is a permanent feature of the population at that point. This is important, and 

 one is made to reflect upon how many possible sets of these local permanent dif- 

 ferences there may be in a population with a geographic range possessed by 

 many organisms. In my experience it has been certain that in nature it was 

 by no means easy to obtain identical materials from different locations, hence 

 the necessity of the standard locations for the source of the organisms for investi- 

 gation. My experience with L. mulfitceniata, signaticollis, decemlineata, unde- 

 cimlineata, and others shows the diversity in the strains from different locations 

 with regard to minor factorial composition in many characters of all kinds. 



Any analysis of the situation, as is made here, only gives the state of hetero- 

 geneity as it exists at present — some indication of the agents that are operative 

 in the production of the results — but no proof of how the state discovered was 

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