24 



PHYSICAL BASIS OF HEREMTY 



green pods, gray versus white-skiniied peas, yellow versus 

 green cotyledons (seen through the sMn of the seed), 

 and round versus wrinkled seeds (determined by the 

 nature of the cotyledons within the seed coat). 



The 3 : 1, 2^2) ratio characteristic for a single pair of 

 characters is the expectation based on the chance meeting 

 of either one of two kinds of eggs with either one of two 

 kinds of pollen grains. In actual numbers this ratio is, 

 of course, not always exactly realized, but only approxi- 

 mately. For the seven pairs of characters that Men- 

 del examined, the F^ ratios were as f oUows : 



The following collective data for the inheritance of 

 color of the cotyledons of garden peas show that the 

 approximation to a 3 to 1 for the recessive character is 

 very close: 



Yellow 



Green 



Total 



No's, per 4 Probable errors 



Mendel 



Correns 



Tschermak. . 



Hurst 



Bateson 



Lock 



Darbishire . . . 

 Darbyshire . . 



White 



Correns 



Tschermak. . 



Lock 



Darbishire . . 



Correns 



Lock 



Totals 



6,022 



1,394 



3,580 



1,310 



11,903 



1,438 



109,060 



1,089 



1,647 



1,012 



3,000 



3,082 



222 



2,405 



50 



2,001 

 453 



1,190 

 445 



3,903 

 514 

 36,186 

 354 

 543 

 344 

 959 



1,008 



1,856 



70 



850 



8,023 

 1,847 

 4,770 

 1,755 

 15,806 

 1,952 

 145,246 

 1,443 

 2,190 

 1,356 

 3,959 

 4,090 

 7,518 

 295 

 3,250 



3.002 : 

 3.019 : 

 3.002 : 

 2.986 : 



3.012 : 

 2.947 : 

 3.004 ; 

 3.019 : 

 3.008: 

 2.985 : 

 3.0;sl ; 

 3.014 : 



3.013 : 

 3.051 : 

 2.954 ; 



0.998 

 0.981 

 0.998 

 1.014 

 0.988 

 1.053 

 0.996 

 0.981 

 0.992 

 1.015 

 0.969 

 0.986 

 0.987 

 0.949 

 1.046 



±0.0130 

 =b 0.0272 

 ±0.0169 

 ±0.0279 

 ±0.0093 

 ±0.0264 

 ±0.0030 

 ±0.0308 

 ±0.0250 

 ±0.0319 

 ±0.0186 

 ±0.0188 

 ±0.0135 

 ±0.2151 

 ±0.0205 



218,425 



50,676 



203,500 



3.004 : 0.996 



= 0.0026 



