Analysis of Heterogeneity in Some Simplest Charactees 193 



minor areas or component centers ; are common to the species in the group. To 

 varying degrees these areas enter into combination with other areas in the for- 

 mation of the general color-pattern, especially b and d, and these combinations I 

 shall consider later. 



(1) Are the differences found in the simplest characters, c, d, and h, quantita- 

 tive or qualitative f — The spots meet in a fair way the idea of unit-characters in 

 that they behave quite independently in many processes, and are either present 

 or absent in their entirety; as far as known are indivisible, and in heredity 

 behave as allelomorphs ; are present or absent, and the presence of one of these 

 spots in crossing is dominant to its absence, satisfying fully the conception of an 

 allelomorphic pair, but of the simplest kind. The characters meet all of the 

 concepts as to the nature of the most elemental manifestations of gametic consti- 

 tution as held by the neo-Darwinians. Their invariable position in these ani- 

 mals shows them to be characters whose positions and relations are, and have 

 been for a long time, conditioned in the germinal material. In every way they 

 are comparable to warts, wens, or other extremely localized attributes so often 



k; k; kIa'" 



Fig. 12. — Showing the pronotum of the 

 lineata group in Leptinotarsa and location of 

 the different centers of color formation. The 

 designations are purely empirical, but are 

 those used throughout the text to denote ele- 

 ments of this complex system. 



discussed by the Weismannians as certain proof of the existence of conditioning 

 entities in the " germ-plasm," and whose variations, which must form the basis 

 of their transmutations, are " ultimately quantitative." 



The question whether the small variations of these characters are quantitative 

 or qualitative is far reaching and of fundamental importance in the analysis of 

 transmutation phenomena, and in heredity and evolution. Putting aside opin- 

 ions as to the manner in which the various attributes are conditioned in the 

 germinal material, only admitting that they are in some manner so conditioned, 

 the conception of Weismann that all variation is ultimately quantitative is 

 clearly shown in his statement in The Evolution Theory, vol. II, pp. 151-3. 



The standpoint that there are two distinct kinds of variation in organisms 

 quite independent of one another, quantitative and qualitative, has been clearly 

 stated by De Vries. 



The clearness of De Vries's statements and argument leaves not the slightest 

 room for doubt as to his position and his belief in the existence of two entirely 

 distinct kinds of variation, whose behavior centers around the unit-character. 

 The fluctuations of one of these characters must, by De Vries's proposition, be 

 plus and minus, always in line, the mutations in many directions or multifarious. 



