PARTIAL DICLINISM. 223 



protandrous ; (2) that variation in size of the flo\vers has 

 always taken place, not among the flowers on a single plant, 

 but between the flowers on different individuals." 



Mr. Darwin suggests another view : * " As the production 

 of a large supply of seeds evidently is of high importance 

 to many plants, and . . . the females produce many more 

 seeds than the hermaphrodites, increased fertility seems to 

 me the more probable cause of the formation and separation 

 of the two forms." 



" S. M.," reviewing Mr. Darwin's work in the Journal of 

 Botany, 1877, p. 375, "felt compelled to differ from the 

 author, and adds, " For ourselves we cannot help thinking 

 that gynodioecism can be better explained on the view of a 

 suflicieucy of pollen for the fertilisation of all the individuals 

 of a species being produced by only a few of the flowei'S, 

 so that instead of some of the anthers of all the flowers 

 becoming abortive — a very common occurrence — we see here 

 abortion of all the anthers of some of the flowers. . . . All 

 known instances of gynodioecism relate to species Avhich 

 have the maximum of stamens possessed by the orders to 

 which they relatively belong, and are without any complex 

 entomophilous structure. . . . We may also remark on the 

 pauciovulate condition of gynodicecious species, and ask why 

 do we not see this form of sexual separation in multiovulate 

 ones ? " 



In reply to this writer's suggestions, I would remark 

 that in all entomophilous flowers far too much pollen is 

 produced and Avasted ; that Mr. Darwin's observation, that 

 a bee could fertilise ten pistils with pollen from one flower 

 of Satureia, might readily apply to hundreds of cases where 

 no g^-nodioecism exists ; and as long as insects visit flowers 

 the tendency is not to contabescence and abortion of the 

 * Forms of Flowers, p. 304. 



