332 J. ARTHUR HARRIS 



TABLE i 

 Relationship between seed and ovule number in Robinia. 



of pistillate flowers increases as the total number of flowers per inflo 

 rescence increases. In Ficaria the relative number of pistils increases 

 as the total number of sporophylls becomes larger. 



Dr. BLAKESLEE and I (1918) have applied this coefficient to the deter 

 mination of the relationship between the total annual egg production 

 and the monthly egg production of White Leghorn fowl. We have there 

 shown by means of this coefficient that the winter months, November, 

 December, January and February, and the following autumn months! 

 August, September and October, show an increase over their theoretical 

 quota of eggs when the annual total egg production rises above the 

 normal. That is, r eg , the correlation between total annual egg produc 

 tion and the deviation of the monthly production from its probable value, 

 is on the whole significantly and substantially positive. The spring and 

 summer months, April, May, June and July, show negative values of 

 r n , that is, they make a lower relative contribution to the annual total 

 than might be expected when the total varies in the direction of an in 

 crease above the normal egg production of the flock as a whole. 



FURTHER ILLUSTRATIONS 



Illustration i. Proportionality of parts in Paramccinm 

 JENNINGS (1911) in his masterly investigation of assortative mating 

 in Paramecium, has given data for determining the relationships between 



