vili PREFACE TO THE EEPEINT OF 1884. 



the first rank in the chain of causes to dichogamy. 

 Similar views are given in the present edition, p. 283, 

 in connection with observations by Hildebrand, 



In a subsequent paper (' Botan. Centralblatt,' 1880, 

 iv., p. 829) he describes a similar gynodicecious 

 condition in some Stellarias and Cerastiums. Here 

 there are pure female, semi-female, and hermaphrodite 

 plants, the flowers of the female form being smaller 

 than those Df the others. This distribution of sex he 

 calls " gynodimorphism," a condition which he des- 

 cribes (' Bot. Centralblatt.,' 1880, p. 1021) as occurring 

 in Arenaria ciliata and Alsine verna. 



F. Ludwig (' Kosmos,'* 1880-81, viii., 357) describes 

 two forms of Erodiwm cicutarium. The first, which is 

 distinguished by having nectar-guides, is protandrous, 

 and adapted for fertilisation by insects. The second 

 form is weakly protogynous and autogamic. This 

 form has no nectar-guides, and the petals are usually 

 shed during the day on which the flowers open. It 

 resembles E. moschatwn, which is homogamic (or weakly 

 protogynous). The first form is more like E. macro- 

 denvM, which is markedly protandrous, and where 

 autogamy is impossible. 



Hermann Miiller ('Nature,' xxiii., p. 337, 1881) 

 has shown that Syringa persica is gynomonoeeious, 

 having on the same inflorescence a majority of 

 hermaphrodite flowers of large size, and a minority of 

 small-sized females. 



' Stelliirin glauca and Sherardia arvensis are gyno- 

 diojcious. 



H. Miiller has also written an important paper on Gen- 

 taureajacea (' Kosmos ' x. and ' Nature ' xxv.) in which 

 he publishes his change of opinion as to the origin of 



* See also ' IrmiBchia,' 1881, No. 1, and ' Bot. Centralblatt,' xii. p. 83 

 and viii. p. 87. 



