VARIATION IN DIFFERENT PORTIONS OF PLANT. 



39 



butions given in table 8. We note, however, that primary-branch 

 whorls by themselves are somewhat less variable, both absolutely and 

 relatively, than are the "all-branch" whorls. The means are also 

 slightly higher in the primary-branch than in the "all-branch" distri- 

 butions. This definite system of differences would appear to indicate 

 that whorls on primary branches are as a class differentiated from 

 whorls on other branch divisions of the plant. It will be seen later that 

 this is the case. It should be noted how slight the differences are be- 

 tween the constants for Series I, II, and III, for the portion of the plant 

 under consideration. The means for the three series differ by 0.1 leaf 

 or less, and the standard deviations by < 0.06 leaf. It is clear that 

 these differences are only what would be expected to arise from random 

 sampling, and that there is no sensible, real differentiation between 

 these series. As has been the case in the other portions of the plant so 

 far examined, there is a definite, though not large, divergence between 

 the constants for Series IV and those for Series I, II, and III. Series 

 V and VI fall in a class by themselves. 



Table 16. — Difference table comparing pHmary -branch whorls with main-stem 

 whorls. Totals for seiries. 



Series. 



DiflFerences. 



Between means 

 (unit =1 leaf) 



II 

 III 

 IV 



V 

 VI 



Absolute difference — 0.736±0.064 



Relative difference. . per cent. . . 7.9 



Absolute difference — 1 . 060^r . 063 



Relative difference. . per cent. . . 10.9 



Absolute difference ;-1.092± .071 



Relative difference. . per cent. . . 1 11.2 



Absolute difference. 



Relative difference.. per cent... 



Absolute difference 



Relative difference. . per cent... 



Absolute difference 



Relative difference.. per cent... 



.561± .078 



5.9 

 .550± .093 



fi ^ 

 — .330± .080 



3.6 



Between stand- Between coeffi- 

 ard deviations cients of vari- 

 (unit = 1 leaf). ation. 



0.137±0.045 



12.9 



.396± .044 



49.4 

 .460± .050 



67.0 

 .304±: .041 



43.2 

 .103zt .066 



8.0 



.120± .057 



9.9 



2.579±0.502 



22.6 

 5.555± .475 



67.5 

 6.230± .555 



88 2 

 3.867zfc .435 



52.3 

 2.244± .795 



15.3 

 1.864± .648 



14.0 



The main-stem whorls form a definite base with which the primary- 

 branch whorls may be compared. This comparison is made in table 16, 

 which is a "difference table" corresponding in plan to table 9 above. 

 In this case the differences are given the positive sign when the primary- 

 branch constant is the greater. The relative difference is in each case 

 the percentage which the absolute difference is of the main-stem con- 

 stant. Only the totals for the series are compared. 



Considering the first four series, we see that both absolute and relative 

 differences are large. There can be no doubt that they are significant. 

 In Series V and VI the differences are smaller, but still probably in all 

 cases significant. We conclude, then, that primary-branch whorls as 



