THE GERANIUM FAMILY. 185 



particulars from Tropaeolum and Impatiens, both of which, in 

 recognition of their wide departure from more primitive forms, 

 are now placed in separate families. The study of such a series 

 of forms is in the highest degree instructive, presenting as it 

 does very important evidence regarding the descent of these 

 peculiarly modified genera. 



