EDITORIAL STA'l i:\li V 



laws of heredity and evolution; (2) that in the study of variation it i- necessary to 

 go beyond the biometrician's curve to :i knowledge of "the history of tin- individual 

 phenomenon"; (3) that dominance is a thing of many degrees, :md i- f.-ir f 

 representing a natural law; (4) that in wider crosses, at i.-nded inherit., 



seems to be the more general phenomenon; (5) that very many gr .-, s of 



"fertility" exist; (6) that apparently some of the most interesting fact- .,; 

 opment can be learned only through a utilization of such known gradations of 

 fertility; (7) that males only (or almost exclusively) result from numerous crosses 

 in which fertility ("germ compatibility") is much reduce,! |,\- a choice of birds 

 widely separated in the pigeon group. 



The more important conclusions of the seventh paper the extruded M-ri. 

 short statements, not really in manuscript form were as foil. It hat fertility 



("germ compatibility" and "germ strength") in its varying 

 associated with the production of sex and color; (2) that fertility varies much in 

 individuals of the same species, at different ages and at different .-tages of tin- 

 season; (3) that in general the "stronger germs" arise toward the lir>t of tin- 

 season and tend to produce males; the "weaker germs" produced in late -ummer. 

 especially by birds "overworked at reproduction," tend to produce females (and 

 more white color); still later there is a tendency to a production of eggs capable 

 of little or of no development; (4) that there is a predominance of males from the 

 first egg and of females from the second egg of the pigeon's clutch; 5 (">) that tin- 

 male goes further in development and arises from a "stronger germ" than d 

 the female; (6) that strength in the parents tends, among pigeons, to produce male 

 offspring; (7) that inbreeding in pigeons leads to the production of \\eaker germ-: 

 (8) that immaturity and old age in pigeons are also associated with the production 

 of weaker germs; (9) that white color, albinism, and color "mutations" may a: 

 by quantitative variation, from the weak germs incident to inbreeding, old 

 and lateness of season; and that such quantitative variations mutatioi, 

 proved to be of genetic value; and, furthermore, that with pigeons, by simple 

 known means, one should be able progressively to shift the "strength" of their 

 germs so as to secure either a greater or a smaller number of these mutations." 

 In other words, Whitman's later studies constitute a discovery and a partial analy- 

 sis of certain means of so modifying the germ-plasm as to carry it from one develop- 

 mental and hereditary capacity to another; and in the light of ti -ults t<> 

 affirm continuity, quantitativeness, and fluidity regarding the 1> the heredi- 

 tary characters in question fertility, sex, and color. This, too, at a time when 

 very many of his fellow biologists have, in large measure, been closely commr 

 to the view that discontinuity, qualitativeness, and fixity are the essential bases 

 of hereditary phenomena. 



These latter interpretations are, of course, currently thought to 1 .ally 



well founded in connection with the heredity of sex. It is of t he highesi 

 therefore, that sex is one of the characters which has apparently been thus apprtud 

 mately brought under control. 



'This is true for many "pure (wild) species"; see a further sMtrm.-nt at the clos." of ("h:i|>t,-r XIII 

 3A more complete consideration of "mutations" il jmffl in Vol.,,, 

 only in so far as they are one -a rather infrequent one-^of the several ,,h. 



