18 THE TRUE GRASSES. 



among the entirely hermaphrodite species. Many 

 genera (Alopecurus, Anthoxanthum, Pennisetum, Spar- 

 Una) are strongly proterogynons ; inmost cases, how- 

 ever, the anthers protrude earlier and discharge the 

 greater part of their pollen, especially by turning over 

 suddenly, before the stigmas are visible. When these 

 emerge at the sides of dependent or nodding spikelets 

 they are directed upwards, and consequently only the 

 pollen from flowers situated higher up can come in con- 

 tact w T ith them. More rarely the stigmas project from 

 the apex of the spikelet, and then mainly in the proter- 

 ogynous and monoecious species. In some hermaphrodite 

 flowers cross-fertilization is so much the rule that they 

 have lost the power of effectual self-fertilization, as in 

 Rye. In the majority of cases, however, both kinds of 

 fertilization seem at least to be possible ; for example, the 

 species of Wheat are usually self-fertilized, but may also 

 be adapted to cross-fertilization, since their glumes are 

 open above, the stigmas project laterally, and the an- 

 thers empty only about -J of their pollen in their own 

 flower and the rest into the air. Cross-fertilization is 

 much more rare and difficult in Barley, and in certain 

 races like the six-ranked, the short-spiked two-ranked, 

 and the peacock Barley, the flowers, especially in our 

 climate, never open, and consequently cross-fertilization 

 is made impossible. Again, Leersia oryzoides Swz. and 

 Amphicarpum Purshii Kunth, are strongly cleistogamic ; 

 in both there are two kinds of inflorescence ; the con- 

 spicuous terminal panicle of the culm is perfectly sterile, 

 but the lateral inflorescence of Leersia, which remains 

 covered by the sheath, is abundantly fertile ; in Amphi- 

 carpum the fertile spikes are upon short scapes close to 

 the ground, and seem to be fertilized and mature under 

 ground. Diplachne perotina Link., Danthonia spicufa 

 Beauv., Stipa juncea L., etc., are also cleistogamic species. 

 The Ovule. — The ovule is grown to the ventral suture 

 of the carpel without a funiculus. The point of union may 

 be confined to a narrow place at the base, or may vary so 

 far as to reach to the other end of the ovule (Fig. 6, A). 

 The ovule itself is hemitropous (slightly campylotropous), 



