Referate. 



321 



Jf'n/si'/t EjL' :■: Solid Color gave in Fi comjjlete dominance of Solid Color. 

 The Fa generation approximated 3 : i, there being 3 of the Solid Color to 

 I of the Watson type. 



Small J'Ai- Holstein gave in Fi the Large Eye type. Only one cross 

 was made and the Fo numbers were very small. 3 Holstein, 4 Large Eye 

 and I Small Eye individuals were produced. SPII.I.M.AN looks upon this 

 scant data as showing the possible presence of a 1:2:1 ratio, Large Eye 

 being the heterozygote between the two parents. 



Four hypotheses have been formulated to explain these results, all of 

 which, though apparently differing from one another, are in reality in 

 exact agreement so far as the statistical data are concerned. In all four 

 of them two pairs of factors are postulated to account for the manner in 

 which the pigment patterns are inherited. The difference between them 

 lies, not in relation to any actual data which the author possesses, but in 

 their relation to something which is as yet hypothetical, namely, — the 

 functions of certain cell organs. 



As a type of these four analyses, one may take the following inter- 

 pretation. Suppose the Small Eye type by re]iresented by the formula 

 wwhh, then the Holstein Eye differs from it by possessing one dominating 

 factor, — or function as the author would say, — and the Watson Eye 

 differs from it by having another dominant factor. The three zygotic 

 formulae, therefore, may be represented in this manner: 

 Watson Eve .... WWhh 

 Holstein Eye . . . wwHH 

 Small Eye .... wwhh 

 Further, since the solid color differs from the Holstein Eye by one dominant 

 factor and from the If'atson Eye by one dominant factor, its zygotic for- 

 mula may be represented by the term WWHH. 



The only complication in the data is the action of the H factor. In 

 the heterozygous condition (Hh) it appears to enlarge the 1 igmented area 

 only half of what it does when in the homozygous condition. It is un- 

 known whether or not the W factor acts in a similar manner. 



The author restates his views on the meaning of the word "factor" 

 as used in Mendelian analysis. For exemple, by "presence of a factor" 

 and "absence of a factor" it is not meant to imply the presence (W) of a 

 material body in one race and its absence (w) in another, as he believes ("^) 

 some observers think It rather refers to the difference in the manner 

 and the conditions under which the same cell organ functions in different 

 races. Thus (W) represents a certain cell organ performing a specific 

 function under specific conditions, while (w) represents the same kind of 

 a cell organ in another race, which does not perform this specific function 

 under the particular conditions of the first mentioned race. This term (w) 

 does not necessarily mean the inability to perform the function that is 

 performed in the first race, but simply that it is not performed. "Presence" 

 then, according to the writer's idea means the performance of a function, 

 while "absence" implies its nonperformance. In this paper, one secures a 

 more definite idea of Dr. Sl'll.l.Ji.\N's beliefs in reference to a physical 

 basis of inheritance than from any of his preceding papers. 



In the opinion of the reviewers, Dr. SiMl.l.M.VN's position as a critic 

 of the supposed beliefs of other Mendelian writers is unsound. He would 

 entangle Mendelian interpretation — in which a factorial notation with no 

 presumption as to the nature of these factors has been used as a con- 

 venience — with the chromosomes before such entanglement is justified l>y 



