12 rNTEODUCTION. 



was in function a male. The separation of the sexes, 

 however, is not complete in the Ash ; for the female 

 flowers include stamens, which drop off at an early- 

 period, and their anthers, which never open or dehisce, 

 generally contain pulpy matter instead of pollen. On 

 some female trees, however, I found a few anthers con- 

 taining pollen-grains apparently sound. On the male 

 trees most of the flowers include pistils, but these like- 

 wise drop off at an early period ; and the ovules, which 

 ultimately abort, are very small compared with those 

 in female flowers of the same age. 



Of the other or monoicous sub-group of polygamous 

 plants, or those which bear hermaphrodite, male and 

 female flowers on the same individual, the common 

 Maple (Acer campestre) offers a good instance; but 

 Lecoq states * that some trees are truly dioecious, and 

 this shows how easily one state passes into another. 



A considerable number of plants generally ranked 

 as polygamous exist under only two forms, namely, as 

 hermaphrodites and females ; and these may be called 

 gyno-dioecious, of .which the common Thyme offers a 

 .good example. In my seventh chapter I shall give 

 some observations on plants of this nature. Other 

 species, for instance several kinds of Atriplex, bear on 

 the same plant hermaphrodite and female flowers ; and 

 these might be called gyno-monoecious, if a name were 

 desirable for them. 



Again there are plants which produce hermaphrodite 

 and male flowers on the same individual, for in- 

 stance, some species of Galium, Veratrum, &c. ; and 

 these might be called andro-monoecious. If there 

 exist plants, the individuals of which consist of her- 

 maphrodites and males, these might be distinguished 



/ 



* ' G&grapliieBotnnique,' torn; v. p. 307. 



