HISTORICAL DEVELOPMENT OF FLOWER POLLINATION 23 



Eggers, Henslow, Meehan, Coulter, Bush, Battandier, Errera and Gevaert; on 

 self-sterility by Gentry, Warming, Meehan, Delpino, Ludwig, Schneck, Rimpau, 

 Liebenberg, Hoffmann, Neubert, Focke, Eggers, Hunger, Battandier ; on self-fertility 

 by Pedicino, Comes, Meehan, Camel, Wilson, Henslow, Asa Gray, Delpino, Ludwig, 

 Hoffmann; on the relations between crossing and self-fertilization by Henslow, 

 Meehan, Pedicino, Caruel, Comes. Cultivation and pollination researches were 

 carried out by Hoffmann, Wilson, Rimpau, Liebenberg, Beal, Vilmorin, Ottavi, 

 Horvdth. 



Within a few years after the appearance of the first of Miiller's works, Errera 

 and Gevaert were able to publish a summary of the various arrangements for 

 pollination known up to 1878, in their work 'Sur la structure et les modes de 

 fdcondation des fleurs' (Bui. Soc. roy. bot., Gand, xvii, 1878). Loew ('Ein- 

 fuhrung,' pp. 324-7) gives this summary as follows: — 



I. MONOMORPHOUS INDIVIDUALS, i.e. in respect of flowers all the indi- 

 viduals are alike. 



1. Monomorphous Flowers. All flowers alike, and hermaphrodite. 



A. Cleistogamy (Kuhn). All the flowers remain permanently closed; 

 crossing is impossible. 



B. Chasmogamy (Axell). All flowers open ; crossing is always possible. 

 {a) Direct Autogamy. The pollen falls directly on the stigma of the same 



flower, 

 a. Direct Autocarpy. Self-pollination is effective : Trifolium arvense. 

 /3. No direct Autocarpy. Self-pollination is not effective : Cory dalis cava. 

 (V) No direct Autogamy. The pollen does not fall directly on the stigma. 

 a. Herkogamy (Axell). The mature anthers and stigmas are remote from 



one another : Anacamptis pyramidalis. 

 /3. Dichogamy (Sprengel). The anthers and stigmas are mature at different 

 times. 

 * Proterandry (Delpino). The anthers open before the stigmas are ready 



for pollination : Teucrium Scorodonia. 

 ** Proterogyny (Delpino). The stigmas are ready for pollination before 

 the opening of the anthers : Aristolochia Clematitis. 



2. Pleomorphous Flowers. The flowers of various individuals are different. 



A. Chasmo-Cleistogamy (Delpino). The constantly hermaphrodite flowers 

 differ from one another in the mode of pollination, some being cleistogamous, others 

 chasmogamous : Oxalis Acetosella. 



B. Monoecism. The flowers of the same stock differ from one another in 

 sex : there are always a few flowers that are not hermaphrodite. 



(a) Dimonoecism. The flowers of the same individual are of two kinds, 

 a. Andromonoecism (Darwin). Flowers hermaphrodite and male : Veratrum 



album. 

 ^. Gynomonoecism {p^rwrn). Flowers hermaphrodite and female : Parietana 



ofiicinalis. 



