v iii PREFACE TO THE REPRINT OF 1884. 



the first rank in the chain of causes to dichogamy. Simi- 

 lar 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 gynodioecious condi- 

 tion 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 

 of the others. This distribution of sex he calls " gyno- 

 dimorphism," a condition which he describes ('Bot. 

 Centralblatt,' 1880, p. 1021) as occurring in Arenaria 

 ciliata and Alsine verna. 



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

 scribes two forms of Erodium cicutarium. The first, 

 which is distinguished by having nectar-guides, is pro- 

 tandrous, and adapted for fertilisation by insects. The 

 second form is weakly protogynous and autogamic. 

 This form has no nectar-guides, and the petals are usu- 

 ally shed during the day on which the flowers open. It 

 resembles E. moschatum, which is homogamic (or weak- 

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

 denum, which is markedly protandrous, and where auto- 

 gamy is impossible. 



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

 has shown that Syringa persica is gynomonrecious, hav- 

 ing on the same inflorescence a majority of hermaphro- 

 dite flowers of large size, and a minority of small-sized 

 females. 



Stellaria glauca and Sherardia arvensis are gyno- 

 dicecious. 



H. Miiller has also written an important paper on 

 Centaurea jacea ('Kosmos/ x., and 'Nature,' xxv.) in 

 which he publishes his change of opinion as to the origin 



See also 'Irmischia,' 1881, No. 1, and 'Bot. Centralblatt,' xii. p. 

 83, and viii. p. 87. 



