THE ASSOCIATION OF CHARACTERS 307 



primroses with the remaining qualities of the plants, we 

 observe a definite case of correlation. Small capsules are the 

 product of weak stems, long ones are borne only by stout 

 individuals. A curve, made for the height of the plants 

 would run nearly parallel to that of the capsules. Com- 

 paring weak branches with the main spike, we find the same 

 arrangements, the capsules on the former being decidedly 

 smaller. I have made some cultures with this species in 

 order to study the correlation of the capsules and the general 

 degree of development under the influence of different 

 outer conditions of life. By giving more manure, a better 

 exposure, or more adequate treatment, it is easy to get much 

 stouter stems, with a richer system of branches and increased 

 foliage. Along with these marks the capsules are seen 

 to increase in size, their medium length coming up from 

 2.5 to 3.5 cm. and their maximum reaching even 4.5 cm. 



It is evident that the growth of the capsules in part 

 runs parallel with that of the other organs of the plant, 

 and in part depends upon them. A stouter stem, with 

 larger and more numerous leaves, produces more nourish- 

 ment for the flowers and fruits and thereby will make them 

 bigger. On the other hand, the tall individuals are largely 

 those which have found, from their very youth, the most 

 favorable conditions of soil, of water, of exposure, and of 

 other influences, and inasmuch as these factors are still 

 at work during the responsive period of the development 

 of the fruits, they will directly affect them in the same 

 direction. Thus we see that in such cases the causes of 

 correlation are twofold, the one acting directly, the other 

 indirectly, and influencing the younger organs through the 

 degree of development of the older ones. 



Returning to the sugar beets, we may give our attention 

 to the correlations which the two main points in their life 

 may exhibit with the more easily appreciated characters 



