568 THE FERTILISATION OF FLOWERS. [PART ILI. 
‘Orv. GRAMINEL. 
This whole order consists of plants with well-marked anemo- 
philous flowers. . I have, however, often observed a small fly 
(Melanostoma mellina, L.) busy upon the anthers of various grasses 
(Anthoxanthum odoratum, Poa annua, Festuca pratensis, Agrostis 
alba). Bromus mollis and Brachypodium pinnatun are visited by 
beetles (590, I:). Many grasses are proterogynous, ¢.g. Anthoxan- 
thum odoratum, Alopecurus pratensis, Nardus stricta (351, p. 19). 
Oryza clandestina is PORE ENC for possessing cleistogamie flowers 
(759). 
Secale cereale-—Anthers and stigmas mature simultaneously. 
The flowers expand widely, and the essential organs protrude 
freely ; cross-fertilisation can consequently be effected on a very 
large scale by the wind (180).? 
Triticum vulgare, L._—Anthers and stigmas mature simulta- 
neously, but the flowers only expand partially and for about a quarter 
of an hour; they then close up permanently. The flower opens 
suddenly, scattering all its pollen, about one-third of which remains 
within the flower while the other two-thirds are shaken out. 
Cross-fertilisation can only be effected by the wind to a much less 
extent than in the preceding species, and Delpino has found by 
experiment that self-fertilisation leads to the. production of good 
seed. The flowering period lasts four days, and since each flower 
only expands for a quarter of an hour, a very small fraction of the 
flowers are expanded at any one time (180). 
Hordeum vulgare.-—The flowers in the two intermediate rows 
never expand ; those in the four outer rows behave like the flowers 
of wheat (180). 
Hordeum distichum.—While in H. vulgare all the flowers are 
hermaphiodite, only those in the two central rows are so in 
HT. distichum. They also remain closed and fertilise themselves; 
but occasionally normal open flowers occur among them, which may 
then be cross-fertilised by pollen from the male flowers in the 
four outer rows (180). 
Hordewm and Cryptostachys have cleistogamic flowers ( 167) 
1 Ascherson, Botanische Zeitung, p. 350, 1864. 
* Kornicke, in Regel’s Gartenflora, p. 20, 1866. 
