3Q INTRODUCTION 



a. The flowers all remain permanently closed : archo-cleistogamy (Knuth). 

 j3. Besides cleistogamous flowers there occur others that are chasmoga- 



mous : chasmo-cleistogamy (Delpino). 

 y. The flowers remain closed only ilnder certain circumstances : pseudo- 

 ckistogamy (Hansgirg). This may occur. 



(a) In consequence of deficiency of light : photo-cleistogamy. 



(|3) In consequence of a high water-level : hydro-cleistogamy. 



(y) In consequence of insufiicient warmth : thermo-cleistogamy. 

 8. The flowers open a little : hemi-cleistogamy (Knuth). 



(a) The stamens project : chasmanthery ^ 



(/3) The stamens remain enclosed : cleistanthery \ 



C. In the same species monoclinous and diclinous flowers occur : Polygamy 

 (Linnaeus). 



1. All the floral forms occur on the same plant. 



a. Hermaphrodite and male flowers occur : Andro-monoecism (Darwin). 



b. Hermaphrodite and female flowers occur : Gyno-monoecism (Darwin). 



c. Hermaphrodite, male, and female flowers occur: Coeno-monoecism 



(Kirchner). 



2. Monoclinous and diclinous flowers appear on different plants. 



a. Hermaphrodite and male plants occur : Androdioecism (Darwin). 



b. Hermaphrodite and female plants occur : Gynodioecism (Darwin). 



c. Hermaphrodite, male, and female plants occur : Trioecism or trioecious 



polygamy (Darwin). 



By the researches of F. Ludwig, O. Kirchner, A. Schuiz, and E. Warming, 

 besides the already mentioned modes of distribution of the sexes numerous others 

 have been made known. In particular, it appears from the observations of these 

 investigators that many plants may be simultaneously andromonoecious and andro- 

 dioecious, or gynomonoecious and gynodioecious,or at the same time andromonoecious, 

 androdioecious, gynomonoecious, and gynodioecious. For such cases Loew 

 (Humboldt, viii, pp. 197 et seq.) has proposed the term Pleogamy. 



We are especially indebted for important researches on this subject to Aug. 

 Schuiz, who has published them in his ' Beitrag zur Kenntnis der Bestaubungs- 

 einrichtungen und Geschlechtsverteilung bei den Pflanzen,' I and II (Bibliotheca 

 botanica, Nos. 10 and 17). The most important of the instances recorded by 

 Schuiz are summarized by Loew (' Blutenbiol. Floristik,' pp. 377-81) as follows : — 



Group I. — In many stocks that are fundamentally hermaphrodite, the stamens of 

 all the hermaphrodite flowers degenerate ; on others, this is the case only in certain 

 flowers. The individuals are therefore of three kinds : Hermaphrodite, female, 



' The terms cleistanthery and chasmanthery, having already been used in another sense, must 

 retain this by right of priority. Ascherson (Ber. D. bot. Ges., x, 1892) applies the term chasmantherous 

 to those cleistogamous flowers in which the anthers dehisce, shedding their pollen-grains on to the 

 stigma, where they germinate (e. g. in Vicia angnstifolia) ; the term cleistantherous, on the other 

 hand, is applied to those cleistogamous flowers in which the anthers do not dehisce, so that the 

 pollen-tubes are obliged to penetrate the anther walls before they can reach the stigma. 



[Knuth does not devise fresh terms to replace those superseded. Cryptantherous and erypt- 

 anthery, phaenantherous and phaenanthery, are here suggested. — Tr.] 



