H. BOTANY AND HORTICULTURE. 359 



pended from long filaments open at the base, and shed their 

 contents when moved by the least breath of wind ; the feath- 

 ery stigmas expose a large surface, with numerous hollows 

 and projections, upon whicli the pollen may lodge; and thus, 

 in very many cases, cross-fertilization is almost inevitable. 

 The same result is often aided otherwise, as has been recent- 

 ly shown by Prof Hildebrand, of Freiburg, following Delpino, 

 of Florence. Dioecious grasses (in which the male and female 

 flowers are on separate plants) are few, but many monoe- 

 cious species are made, in effect, dioecious as respects fertili- 

 zation, either by the male flowers at the top of the stem los- 

 ing their pollen before the female flowers below have exserted 

 their stigmas, as in Indian corn, or by the stigmas preceding 

 the maturing of the anthers, as in Coix lachryma (Job's 

 Tears), or by the position of the male flowers below the fe- 

 male, as in wild rice, or by their wide separation on distant 

 branches. In some species, however, the arrangement seems 

 adapted rather to secure fertilization between the flowers of 

 the same plant. 



So in those grasses where the male and female organs are 

 in the same flow^er. In sweet vernal grass, and various oth- 

 ers, the stigmas are exserted before the anthers, and remain 

 in condition to receive the pollen but for a very short time. 

 In rye, the anthers first slowly appear, and shed a part of 

 their pollen into the air; after some hours the stigmas be- 

 come receptive, by which time the anthers have opened more 

 widely, and the rest of their pollen escapes. Here self-fertil- 

 ization is possible. In wheat, the flower opens suddenly, the 

 anthers appear, let fall a third of their pollen upon the stig- 

 ma, and the rest is dispersed in the air. The whole process 

 is completed in less than half a minute. In the oat, the an- 

 thers hang down outside of the flower and discharge most of 

 their pollen into the air; but in damp and cold weather the 

 flow^ers remain closed, and are self-fertilized. In many other 

 cases the mode of fertilization is likewise determined by the 

 Aveather. In canary grass, the anthers and stigmas appear 

 together, but upon opposite sides of the flower. In other 

 grasses, the stigmas often remain fresh and receptive of j^ol- 

 len from other flowers a considerable time after their own an- 

 thers are emptied. In barley, the flowers remain closed, and 

 are all self-fertilized ; but sometimes those in two rows, out 



