168 On the Selecting Poioer of' Plants 



tites, but consisting wholly of lime. In other respects the quan- 

 tity of earth obtained appeared to keep pace with that in which 

 the plant was supplied with it from without. Thus, the largest 

 amount of lime was from the plants that had grown in Carrara 

 marble, and of silex from those that had grown in sand. On 

 the other hand, the great increase of calcareous salts in the pro- 

 duce of the seeds that had grown up in the garden, in a soil 

 consisting of sulphate of strontian, indicates how much is owing 

 to the quantity of earthy matter brought to it by the rains. 



The following is a tabular view of the results of the above- 

 mentioned experiments : — 



In 183pJ I made similar arrangements to those just alluded to, 

 with the addition of a fourth box, containing washed flowers of 



