INTRODUCTION. 17 



cus ; the second, Samara and Akene ; the third, 

 where the consolidation of seed and seed-leaf is 

 the most perfect, Caryopsis ; and even that is sur- 

 passed, where bract and stem, or calyx, take part in 

 the formation, and the Syncarpium, is the consoli- 

 dation of an entire infloresence. 



8. The distribution of organic functions to dif- 

 ferent individuals, or different parts of the same 

 individual, is often the indication of a degree of 

 evolution. It is a singular fact that since the time 

 of Linne, hermaphrodite flowers have been consid- 

 ered higher in the scale than the diclinic, when in 

 the animal kingdom we justly take an opposite 

 view of the case. The highest position in the line 

 of sexual evolution is found in families like the 

 Grasses and Composite, where the sexes occupy 

 regularly and constantly, the same position in an 

 inflorescence, the male, perhaps with the sole excep- 

 tion of a few grasses, and Euphorbiacese, showing 

 a centripetal, the female a centrifugal tendency. 



The diclinous habit of the Gymnosperms, in every 

 respect the lowest of the Phanerogams, cannot 

 be used as an argument against the high evolution 

 of diclinous plants in general, as their flowers 

 are not yet individualized out of the state of an in- 

 florescence, and partake still in many points of the 

 peculiarities of the Heterosporous Cryptogams. 



9. An established inflorescence, persistent in 

 form, indicates evolutionary progress, as compar- 

 ed to variable or ill-defined forms. For instance, 

 the capitulum of the Composite, the umbels of 



