Harris, Correlation iu the Inflorescence of Sanguiuaria. ()31 



and the correlation between these and a third character would 

 necessarily be of the same general order of magnitude. I fancy 

 it would be well worth while for some one to work out such 

 relationships as we have here in some form in which the numbers 

 of ovules and of seeds are not so nearly the same. 



Indeed the whole field of problems presented by the relationship 

 between somatic characters and fertility and fecundity seems worthy 

 of intensive cultivation. At present our knowledge is very meagre. 

 For animals Pearson 5 ) has secured evidence that tall women are 

 more fertile than short ones, and he tells me that data for other 

 mammals will be published. In agricultural literature much has been 

 written on the amount of straw and grain in cereals, but the methods 

 of experiment and record leave much to be desired. In Nothos- 

 cordium and Allium it has been shown 5 ) that there is a correlation 

 of about -500 or over for length of flowering stalk and number of 

 flowers per umbel. In Cercis 6 ) and Celastrus 7 ), however, when we 

 work within the individual there seems to be no relationship between 

 the size of the inflorescence as measured by the number of flowers 

 produced and the fertility of the ovaries. There must be reasons 

 for differences such as these and it lies before the biologist to 

 find out what they are. 



Size and fertility of fruit - - both number of ovules formed and 

 number of seeds developing - are found to be correlated, the 

 degree of the interdependence being about -500 700. The con- 

 stants for both ovules and seeds are obout -100 higher in 1907 

 than in 1906, possibly due to the somewhat more mature condition 

 of the fruits which must be taken before they are quite ripe if 

 the countings are to be made for the placentae. The constants 

 for length of fruit and number of seeds maturing are slightly higher 

 than those for length of fruit and number of ovules formed, but 

 the difference is of no practical value. 



Since both length and fertility of fruit are correlated with 

 pedicel length there would necessarily be some statistical correlation 

 between length and fertility whether they were in any measure 

 biologically interdependent or not. By means of a suitable formula 

 we can remove the influence of the correlation of the two cha- 

 racters with pedicel length upon their own interdependence. We 

 find that the removal of this factor disturbs only very slightly the 

 values as given above, and conclude that the correlation must be 

 due chiefly to other factors than pedicel length. 



The correlation between the number of ovules formed and the 

 number of seeds developing per placenta or per fruit is high, lying 



5) Harris, J. Arthur. Ann. Kept. Mo. Bot. Gard. Vol. XX, pp. 105115. 1909. 



6) Harris, J. Arthur, Biometrika. In press. 



7) Harris, J.Arthur. Ann. Rept. Mo. Bot. Gard. Vol. XX, pp. 116 122. 1909. 



