102 The Unity of the Organism 



of parts of the fructiferous organs of plants. These meas- 

 urements are of Frasera perryl, an abundant annual in 

 southern California and rather specially favorable for such 

 a study in that the fruit stalk is single in each plant, stands 

 up intact and rigid after it is fully ripe and dry, and is al- 

 most mathematically regular in the disposition of its parts. 

 The table was compiled from measurements of a single plant, 

 and three measurements pertaining to each seed vessel are 

 given, namely, the length of the interval on the main axis 

 between each two vessels, the length of the pedicels which 

 bear the vessels, and the length of the vessels themselves. 

 The measurements are all in millimeters. Several other di- 

 mensions might have been taken, which would almost cer- 

 tainly have produced similar results. 



15 15 21.5 13 



That these gradations hold, at least in some plants, even 

 to the seeds is certain as the following tabulation of the 

 weight of seeds from different parts of the seeding axis of a 

 wild mustard plant (Brassica nigra) shows. The figures 

 were compiled from the weights of seeds taken from groups 



