228 THE STEUCTURE OF FLOWERS. 



Galtha palustris is said to be androdicEcions, but no 

 details are giveu by the observer.* 



Besides the VmhelUfercB,] wbere andi-omonoecisra seems 

 to be a characteristic feature, Miiller mentions Asperula 

 taurina and Galium Crueiaia, Pulmonaria offidnalis, Coriaria 

 myrtifolia,a.nd Diospyrus Virginiana as being andromonoecious. 

 The hermaphrodite flowers of these species are protandrons. 



In Galium Gruciata, Mr. Darwin noticed that the piatil is 

 suppressed in most of the lower flowers, the upper remainiug 

 hermaphrodite. 



Heterostylism may tend to produce the same result when 

 the stamens of the long-styled forms degenerate so far as to 

 become atrophied without the pistil losing its functions. 

 Pulmonaria angustifoUa and Phlox suhulata give hints of this 

 condition.J Asperula scoparia was at first thought by Mr. 

 Darwin to be heterostyled, but finding the anthers to be des- 

 titute of pollen, he considered it to be dioecious. A. taurina, as 

 figured by Mii]ler,§ shows great variability in the lengths of 

 the filaments and styles, and he pronounces it to be andro- 

 monoecious. Hence, as so many of the Buhiaceoe are hetero- 

 styled, there seems every probability of one result of this 

 peculiarity, being one or other kind of this incompletely 

 afEected or partial diclinism. In the case of Coriaria myrti- 

 foUa, Hildebrand found that it was the first flowers which 

 were male only. In Maples, as in Galium Gruciata, the rule is 

 for the three or more flowered corymb to have the central 

 one hermaphrodite, and the lower or outer ones male. This 



* Lecoq, Geog. Bot., torn, iv., p. 488. 



t Miiller says that in Sanicula Europwa the- outer flowers are male, 

 and derelop after the inner ones, which are hermaphrodite. This is so 

 anomalons, that one suspects an error somewhere. I hare not had any 

 opportunity of examining fresh flowers. 



X Forms of Flowers, p. 287. 



§ Fertilisation, etc., p. 303. 



