PREFACE. xvii 



monoecious, and like those of J. regia consist of two 

 sets, one being proterandrous and the other proterogy- 

 nous (Mr. C. G. Pringle, in 'Bot. Gazette/ vol. iv., 1879, 

 p. 237) ; and thus the cross-fertilisation of distinct trees 

 is insured. Mr. Alex. S. Wilson informs me that Silenc 



■ 



inflata is polygamous on Ben Lawers, as he found her- 

 maphrodite, male and female plants. The case is here 

 mentioned because the flowers on the females are small 

 like those on the females in the gyno-dicecious sub-class. 

 In an article in the ' Bull. Torrey Bot. Club/ July, 1871, 

 this Silene is, however, said to be gyno-dicecious. As- 

 paragus officinalis is also polygamous, and the female 

 flowers are about half the size of the male ones; see 

 'Gard. Chron./ May 25, 1878; also Breitenbach, in 'Bot. 

 Zeitung/ 1878, p. 163. 



Several cases can now be added to my list of gyno- 

 dicecious plants, or those which exist as hermaphrodite 

 and female individuals; namely, according to Mr. 

 Whitelegge ('Nature/ Oct. 3, 1878, p. 588), Stachys 

 germanica, Ranunculus, acris, repens, and bulbosus. 

 H. Miiller found on the Alps ('Nature/ 1878, p. 516) 

 Geranium sylvaticum and Dianthus superbus in this 

 state, and the female flowers of the former were of 

 small size. So it is with Salvia pratensis, as he informs 

 me in a letter. I have received an additional account 

 of Plantago lanceolata being gyno-dicecious in England ; 

 and Dr. F. Ludwig of Greiz has sent me a description 

 of no less than five forms of this plant which graduate 

 into one another; the intermediate forms being com- 

 paratively rare, whilst the hermaphrodite form is the 

 commonest. With respect to the steps by which a gyno- 

 dicecious condition has been gained, H. Miiller main- 

 tains by many able arguments (' Kosmos/ 1877, pp. 23, 

 128, and 290) the view which he has propounded; and 

 several botanists think it more probable than the one 



