THE 



AMERICAN NATURALIST 



Vol. XLV June, 1911 No. 534 



INHERITANCE OF FECUNDITY IN THE 

 DOMESTIC FOWL 1 

 DR. RAYMOND PEARL 

 Maine Agricultural Experiment Station 



There are under discussion at the present time two 

 general views regarding certain fundamental points in 

 heredity. Each of these points of view has its zealous 

 adherents. On the one hand, is what may be designated 

 the * ' statistical" concept of inheritance, and on the 

 other hand, the concept of genotypes. By the li statis- 

 tical" concept of inheritance is meant that point of view 

 which assumes, either by direct assertion or by implica- 

 tion, that all variations are of equal hereditary signifi- 

 cance and consequently may be treated statistically as 

 a homogeneous mass, provided only that they conform 

 to purely statistical canons of homogeneity. This as- 

 sumption of equal hereditary significance for all varia- 

 tions is tacitly made in deducing' the law of ancestral 

 inheritance, when individuals are lumped together in a 

 gross correlation table. 2 The genotype concept, on the 

 other hand, takes as a fundamental postulate, firmly 

 grounded on the basis of breeding experience, that two 



