lOO 



Carbon AssimilaiioH. 



assimilatory coefficient. Thus Bonnier and Mangin explain the fact 

 that Boussingault obtained a ratio of ^ of about unity. 



Tablb XXV. 



Assuiiilatoiy Coefficients for Diffeyent Leaves (Bonnier and Mangin). 



In an extended series of observations on the respiration and 

 assimilation of succulents, Aubert (1892) has obtained similar 

 values for the assimilatory coefficient of ordinary plants,*but much 



larger values for succulents. He concludes that the — ^ exchange 



due to assimilation is greater than unity for all plants. For ordinary 

 plants the ratio is not very far removed from unity, but for succulents 

 it niay be much larger. For ordinary plants the ratio varied from 

 1-05 to 1-23, numbers which agree closely with Bonnier and Mangin's 

 observations. Some of the values obtained by him for succulents 

 are given in the accompanying table. The values quoted for Seduni 

 Telephium and Opuntia tomentosa show that at different times the 

 ratio for the same plant may vary greatly. 



Having regard to the peculiar metabolism of succulents, 

 however, the relation of these assimilatory coefficients to the 

 assimilatory process is doubtful. 



