1<)2 



THE AMEBIC AN NATURALIST [Vol. XL V 



terminants, since as soon as the behavior is altered, we 

 at once obtain from the series (2) another type of in- 

 heritance. 



Although we have no clear direct evidence which 

 demonstrates an occurrence of such extreme modification 

 in the behavior of determinants, nevertheless the possi- 

 bility of such an event is amply suggested by the recent 

 experiments. For instance Tower ( '10) has shown not 

 only a reversal of dominance and apparent failure of 

 segregation by merely modifying the environment of the 

 beetles, but also a case in which the same parents pro- 

 duce offspring, some of which follow the law of Mendel 

 while others show entirely different behavior with re- 

 spect to dominance and segregation. Tennent ( '10) was 

 able to obtain from a cross of Hipponoe esculenta with 

 Taxopneustes variegatus, reversal of dominance by de- 

 creasing the alkalinity of the sea water. Numerous 

 samples of this sort can easily be found in the recent 

 literature. 



Whatever be the real condition or conditions which 

 control the behavior of the determinants, one point is 

 clear from the above, that the determinant are not im- 

 mutable in their behavior, but subject to modification. 

 This fact naturally leads us to think that we may obtain 

 various forms of inheritance which are more or less dif- 

 ferent from the type form according to degree of func- 

 tional modification. When a modification is maximum, 

 we may even obtain a case of blended inheritance in a 

 character which normally follows the law of alternative 

 inheritance, or vice versa. 



The facts mentioned above then indicate that our de- 

 duction from the properties of the formula is not at all 

 improbable. 



Again the properties of the formula suggests that we 

 can theoretically connect cases of blended inheritance 

 with those of alternative inheritance by the mere as- 

 sumption that p or q fails to dominate either completely 

 or incompletely. Since as we have shown by the degree 



