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, Caruel, 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, 

 Horvath. 



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 

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

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



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

 viduals are alike. 



L 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. 

 /S. No direct Autocarpy. Self-pollination is not effective : Corydalis cava. 

 ih) 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. 

 l3. Dichogamy (Sprengel). The anthers and stigmas are mature at different 

 times. 

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



for poUination : 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. 



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

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



album. 

 ^. Gynomonoecism (Darwin). Flowers hermaphrodite and female : Parietaria 



officinalis. 



