34-6 OSCAR RIDDLE. 



ably equipped by the distribution of such materials, while one 

 or two are left poorer than the others. 1 A similar conception 

 may be applied to the ova. ' Then upon the union of male and 

 female cell, two oxidizing powers of equal or unequal rank, of 

 higher or of lower degree, meet. A stable (pure breed) high 

 equilibrium results in, say one of four ; a stable (pure breed) 

 lower equilibrium results in another ; while in the other two per- 

 fect equilibrium is not at once attained. 



Here is then a possible picture of the basis of Mendelian segre- 

 gation and proportion, but without recourse to hypothetical 

 "particles" or to immutable and immortal factors. An appar- 

 ently very specific end-result of an oxidation would be traceable 

 in the germ only in the strength or pitch of a general vital process, 

 and not at all in mnemons or representative particles packed with 

 unthinkable precision, order and potentiality into (presumably) 

 the chromosomes. But the above is a possible picture only ; and 

 it is not here my purpose to furnish nor to defend at length a pos- 

 sible or probable theory of the mechanism of heredity. The 

 material in hand lends itself first of all to the demonstration of 

 the impossibility of many Mendelian views. 



The nature of present Mendelian interpretation and description 

 inextricably commits to the " doctrine of particles " in the germ 

 and elsewhere. It demands a " morphological basis " in the 

 germ for the minutest pha^e (factor) of a definitive character. It 

 is essentially a morphological conception with but a trace of func- 

 tional feature. Although heredity is quite surely a functional 

 process of major complexity, it may be recalled that the primary 

 and fundamental Mendelian conception of this process utilizes 

 not a single finding of the science of biochemistry ; that the only 

 physiological fact utilized is the one of certain occasionally ob- 

 served segregation behavior which is exhibited in the end-results 

 of varietal 2 or specific character formation ; such segregation, by 



1 We know that in the corresponding divisions of ovogenesis that extremely dispro- 

 portionate distribution of yolk and cytoplasm occurs quite constantly. We may be- 

 lieve that the laws which there give rise to the extreme differences between polar body 

 and oocyte are not everywhere else, and completely, unoperative ; they may be opera- 

 tive though in a much less pronounced degree in providing different mature ova, 

 and different sperms with varying amounts of the materials mentioned above. 



2 De Vries ('oi, '05) has asserted that only varietal, not specific, differences ex- 

 hibit Mendelian heredity; this statement is not accepted by Bateson ('06), and is 

 controverted by still other workers. 



