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THE AMEBIC AN NATURALIST [Vol. XL VII 



in nutriment, position, etc., are impotent to influence any 

 but dimensional characters, such as length, weight and 

 relative position of units. Inherited characters are 

 affected only by changes in the germinal materials, and 

 such changes might readily be due, as indicated, to 

 inequalities in the distribution of material particles 

 during cleavage. 



Modes of Inheritance in Polyembrvonic Offspring 

 The material for the study of inheritance consists of 

 nearly two hundred sets of quadruplets and the armor of 

 the mothers. Without breeding in confinement, which is 

 not at present practicable, no data concerning paternal 

 inheritance are available. Since, however, there is no sex 

 dimorphism with regard to the characters studied, and 

 since males and females inherit alike from the mothers, 

 one can discover all the essential laws of inheritance 

 governing the polyembrvonic relationship from a com- 

 parison of individuals in sets and of quadruplets with 

 their mothers. After an exhaustive study of this large 

 mass of material the chief general laws discovered are 

 to the effect that single nieristic variates, such as partic- 

 ular scutes, and also aggregates of these elements, as 

 for example the total numbers of these units in a given 

 region of the armor, are inherited in the alternative 

 fashion and show only a minor degree of blending. This 

 is an unexpected result in view of the fact that it has been 

 the general impression that nieristie variations usually 

 exhibit blended inheritance and substantive variations 

 obey the laws of Mendelian inheritance. In this material 

 it has been found that single scutes, recognizable through 

 some marked peculiarity, such as a tendency to split or 

 to fuse with a neighboring element, is inherited as a 

 Mendelian dominant character. If the mother has the 

 character unilaterally or in one band of the armor, one 

 or more of the offspring invariably exhibit the character 

 either unilaterally or bilaterally, either in one band or 

 reduplicated in two or more bands. Again a single scute 



