292 DICECIOUS AND Cbap. VII. 



Seeing how general it is for organs which are 

 almost quite functionless to be reduced in size, it is 

 remarkable that the pistils of the polleniferous plants 

 should equal or even exceed in length those of the 

 highly fertile female plants. This fact formerly led 

 me to suppose that the spindle-tree had once been 

 heterostyled ; the hermaphrodite and male plants hav- 

 ing been originally long-styled, with the pistils since 

 reduced in length, but with the stamens retaining 

 their former dimensions; whilst the female plant had 

 been originally short-styled, with the pistil in its pres- 

 ent state, but with the stamens since greatly reduced 

 and rendered rudimentary. A conversion of this kind 

 is at least possible, although it is the reverse of 

 that which appears actually to have occurred with 

 some Rubiaceous genera and iEgiphila; for with these 

 plants the short-styled form has become the male, and 

 the long-styled the female. It is, however, a more 

 simple view that sufficient time has not elapsed for the 

 reduction of the pistil in the male and hermaphrodite 

 flowers of our Euonymus; though this view does not 

 account for the pistils in the polleniferous flowers 

 being sometimes longer than those in the female 

 flowers. 



Fragaria vesca, Virginiana, Chiloensis, &e. (Rosa- 

 cea 1 ). — A tendency to the separation of the sexes in the 

 cultivated strawberry seems to be mnch more strongly 

 marked in the United States than in Europe; and 

 this appears to be the result of the direct action of 



the two forms. In the female, the These latter plants do not com- 



pistil is perfect, whilst the anthers monly yield any fruit, and are 



are entirely destitute of pollen, therefore in function males. Nev- 



In the polleniferous form, the pis- ertheless, on one occasion Fritz 



til is short and the stigmas never Miiller found flowers of this kind 



separate from one another, so that, in which the stigmas had sepa- 



although their surfaces are cov- rated, and they produced some 



ered with fairly well-developed pa- fruit. 

 pilUe, they cannot be fertilised. 



