BOTH PARENT8 1 LESHY 





8l M MAIIY. 



The progeny of the three mat ings may now be compared i tabli 

 While even very fleshy parents are sometimes hi ius (perhi 



carrying 5 or rarely even 1 zygotic factors for build), yet they do i 

 produce any slender children. The merely "fleshy" parents, od the 

 other hand, produce about 7 per cent slender. None would be expected 

 on the 4-zygotic-factor hypothesis, bul about 6 per cenl would be od 

 the 6-factor hypothesis. 



Table 26. — Summary of selected fleshy matings, together with their prog* 



A comparison of tables 23 and 26 shows a profound difference in the 

 distribution of build in the two sets of progenies. From the matings 

 of slender parents come predominantly (84 per cenl I slender and very 

 slender offspring; from the mating of two fleshy or very fleshy parents 

 come predominantly (67 per cent) fleshy and very fleshy offspring. 

 The ranges of the offspring classes overlap somewhat, for the slender 

 matings produce 16 per cent progeny who are above slender build; 

 and the fleshy matings produce 32 per cent of progeny who are below 

 fleshy build. The progeny of the slender matings are much leas 

 variable than those of fleshy matings. Thus, the standard deviation 

 of the offspring in table 23 is only 3.13 ± 0.17; while the standard 

 deviation of the offspring of the fleshy parents listed in table 24 i- 

 5.74^0.39 and in table 25 4.70 ± 0.52. From the standpoint of 

 genetics this indicates the presence of more genetical factors in the 

 fleshy parents than in the slender. 



However, there is one consideration that must not be overlooked. 

 This is that the mean index of build of the slender offspring is tower 

 than that of the fleshy ones. If we place the average indi I of the 

 very slender and slender groups at 2(1, and of the pure fleshy at 40, 

 then the coefficient of variability of tin- slender and very Blende] 

 3.13-^26, or 12 per cent, and that of the fleshy of table 24 > L70 

 40, or 14 per cent. Thus the fleshy offspring are not only absolutely 

 but also relatively more variable than the slender offspring. 



Perhaps a fairer comparison is obtained from the data ^\ table L2. 

 The standard deviation of the progeny of the S • S inati: 

 L'41 ; of the F X F matings is 5.37. The corresponding coefficients of 



