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THE AMEBIC AN NATURALIST [Vol. XLV 



Darwin's hypothesis of "pangenesis" is in this point 

 very consistent with the Hippocratic view, the personal 

 qualities of the parent or the ancestor in question being 

 the heritage. 



Also the Lamarckian view as to the heredity of 

 "acquired characters" is in accordance with those old 

 conceptions. The current popular definition of heredity 

 as a certain degree of resemblance between parents and 

 offspring, or, generally speaking, between ancestors and 

 descendants, bears the stamp of the same conceptions, 

 and so do the modern "biometrical" definitions of hered- 

 ity, e. g., as "the degree of correlation between the 

 abmodality of parent and offspring." In all these cases 

 we meet with the conception that the personal qualities of 

 any individual organism are the true heritable elements 

 or traits ! 



This may be characterized as the "transmission-con- 

 ception" of heredity or as the view of apparent heredity. 

 Only superficial instruction can be gained by working on 

 this basis. Certainly, medical and biological statisticians 

 have in modern times been able to make elaborate state- 

 ments of great interest for insurance purposes, for the 

 "eugenics-movement" and so on. But no profound 

 insight into the biological problem of heredity can be 

 gained on this basis, for the transmission-conception of 

 heredity represents exactly the reverse of the real facts, 

 just as the famous Stahlian theory of "phlogiston" was 

 an expression diametrically opposite to the chemical 

 reality. The personal qualities of any individual organ- 

 ism do not at all cause the qualities of its offspring ; but 

 the qualities of both ancestor and descendant are in quite 

 the same manner determined by the nature of the "sexual 

 substances"—!, e., the gametes — from which they have 

 developed. Personal qualities are then the reactions of 

 the gametes joining to form a zygote; but the nature of 

 the gametes is not determined by the personal qualities 

 of the parents or ancestors in question. This is the 

 modern view of heredity. 



