640] BODY SIZE AND ORGAN SIZE 



them. Seeds of uniform size were selected and were 

 planted June first. The soil of the plot varied decidedly 

 in fertility, with the result that some of the plants grew 

 luxuriantly, many of them reaching a total dry weight of 

 150 grams, whereas others were much dwarfed, reaching 

 only 4 or 5 grams at maturity. The bulk of the popula- 

 tion were intermediate in size. 



Over two hundred of the plants were harvested from 

 time to time during the summer, representatives of all 

 stages from the young seedling to the appearance of 

 flowers being obtained. The rest, 344 in number, grew to 

 maturity and were harvested then. The number of 

 leaves,- pods and seeds were counted and dry weight de- 

 terminations made of the total bulk of the leaves, of the 

 stem system and of the yield of fruit, separate determi- 

 nations being recorded for total pods (without seeds) 

 and total seeds. From tliese data, the drv wei-ht of the 

 entire i.laut. of thr vcuvtativr shoot and of tli.- ivi>n)- 

 duetixv .tiMietuivs cmld rasilv hr dctrrniin..,!. as wril as 

 the avei-auv wri-lit of Iraf. p.Ml and sred for racli plant. 

 Correlations were thm nia.lc hrlwoni tlio awrage 

 wri-ht of each of these or-ans. re.-~].eet iwly, and the >ize 

 of the ])lant. The latter was reprex-nti'd either by the 

 weight of the shoot (stem i)lus leaves), the weight of the 

 fruit (yield), the number of leaves, the number of pods 

 or the number of seeds. 



Results 



The coefficients of correlation thus determined are set 

 forth in Table I. Eight of these involve the 344 mature 

 plants studied and one (the first) involves the 218 im- 

 mature plants. Three of the correlation tables on which 

 these constants are ])a sod— those showing the relation 

 between shoot weight and (1) average leaf weight, (2) 

 average pod weight and (3) average seed weight in ma- 

 ture plants — are also presented in Tables II, III and IV. 



It will be noted that in every ease there is a positive 



2 Very small leaves, less than one third the average size for the plant, 



