258 CONCLUDING REMARKS CHAP. VI. 



Trees, bushes, and herbaceous plants, both large 

 and small, bearing single flowers or flowers in dense 

 spikes or heads, have been rendered heterostyled. So 

 have plants which inhabit alpine and lowland sites, dry 

 land, marshes and water.* 



When I first began to experimentise on hetero- 

 styled plants it was under the impression that they 

 were tending to become dioecious ; but I was soon forced 

 to relinquish this notion, as the long-styled plants 

 of Primula which, from possessing a longer pistil, larger 

 stigma, shorter stamens with smaller pollen-grains, 

 seemed to be the more feminine of the two forms, 

 yielded fewer seeds than the short-styled plants which 

 appeared to be in the above respects the more mascu- 

 line of the two. Moreover, trimorphic plants evident- 

 ly come under the same category with dimorphic, and 

 the former cannot be looked at as tending to become 

 dioecious. With Lythrum salicaria, however, we have 

 the curious and unique case of the mid-styled form 

 being more feminine or less masculine in nature than 

 the other two forms. This is shown by the large 



* Out of the 38 genera known contain species inhabiting the 

 to include heterostyled species, just-specified stations. So that 43 

 about eight, or 21 per cent., are per cent, of those British plants 

 more or less aquatic in their which have their sexes separated 

 habits. I was at first struck with are more or less aquatic in their 

 this fact, for I was not then aware habits, whereas only 21 per cent, 

 how large a proportion of ordinary of heterostyled plants have such 

 plants inhabit such stations. Het- habits. I may add that the her- 

 erostyled plants may be said in maphrodite classes, from Monan- 

 one sense to have their sexes sepa- dria to Gynandria inclusive, con- 

 rated, as the forms must mutually tain 447 genera, of which 113 are 

 fertilise one another. Therefore aquatic in the above sense, or only 

 it seemed worth while to ascertain 25 per cent. It thus appears, as 

 what proportion of the genera in far as can be judged from such 

 the Linnean classes Monoecia, imperfect data, that there is some 

 Dicecia and Polygamia, contained connection between the separation 

 species which live "in water, of the sexes in plants and the 

 marshes, bogs or watery places." watery nature of the sites which 

 In Sir W. J. Hooker's ' British they inhabit ; but that this does 

 Flora ' (4th edit. 1838") these three not hold good with heterostyled 

 Linnean classes include 40 genera, species. 

 17 of which (i.e. 43 per cent.) 



