344 OSCAR RIDDLE. 



to leave the province of fact, with which the body of this paper 

 deals to enter the realm of assumption and hypothesis. The 

 fact, that in these pages we have been able to get what we are 

 inclined to consider the clearest view that we have at present as 

 to the state in which a character or set of characters exists in the 

 germ, perhaps furnishes a reason why some statement may here 

 be made in regard to the possible mechanism of segregation. 



It has already been stated that to us the phenomena of domi- 

 nance and segregation are only minor, surface, and incidental 

 phenomena of heredity j 1 the really important Mendelian contri- 

 bution being that certain different characters (such as have, ac- 

 cording to my belief, different rather general processes as a basis) 

 of different races may be combined to form new fixed races. The 

 establishment of this last-named fact has been most commonly con- 

 sidered by Mendelians as, on the one hand, a consequence of the 

 laws of dominance and segregation, and, on the other hand, as a 

 strong argument for a " representative particle" basis for these 

 two sets of phenomena. When, however, we learn that a certain 

 character has no other existence in the germ than a rather 

 general protoplasmic power, the " mnemon " conception fails 

 completely and with it the supposed mechanism of its segrega- 

 tion /. e., the shuffling of mnernons in the reduction divisions 

 of the chromosomes. 



How then on my view of the basis of color inheritance may 

 the segregation and proportions which result in Mendelian 

 behavior be accounted for ? I may say at once that I do not 

 know ; but in this respect I consider myself hardly worse off than 

 the wisest Mendelian. My supposition, however, would put less 

 faith than is theirs in the behavior of chromosomes during the 



1 It would seem that instead of viewing the real and entire sea of heredity, learn- 

 ing of its intimate nature, searching its boundaries, sounding its depths, too often 

 Mendelians have to indulge a figure focused their visual instruments upon an 

 optical section lying perhaps a few meters above sea-level. Here, occasionally, 

 beautiful and regular phenomena come into sight; but for the most part the field is 

 blank. At times great ocean swells pass in fine order and precision, permitting the 

 observer to predict quite well some of the attributes of the next undulation and the 

 time of its appearance ; again, bits of spray or foam or mist may sometimes come into 

 view, and the seeming disconnectedness of it all permits the be-focused onlooker to 

 name and classify and wonder. All while the great ocean of heredity with its 

 perfect continuities, its essential oneness, its inclusiveness, lies in unseen constancy 

 and majesty beneath. 



