234 liMSSOJVS WITH PLANTS 



larger kinds, and the foliage is usually harsh or rough. There are 

 many types of sedge-like plants, but the term sedge is commonly 

 restricted to the plants of the group or genus earex, which is con- 

 sidered here. Cariees are very common and abundant. Observe 

 the variation in the number of styles in the various kinds of 

 carex, and determine if the number of stamens varies at the same 

 time. 



XLIV. CROSS -FERTILIZATION 



269. We have found (140) that the purpose of 

 the flower is to produce seeds ; these seeds can- 

 not be formed without the aid of pollen; compara- 

 tively few flowers are perfect and also synanthous 

 (or simultaneous) in the maturation of pistils and 

 stamens, and very many flowers are imperfect. 

 It would seem to follow, therefore, that cross -fer- 

 tilization is the rule, and we infer that it must 

 result in some decided benefit. 



269a. Fertilization or fecundation is the action of the pollen 

 (or generative cells) upon the body which develops into the seed. 



2696. Close-fertilization or self-fertilization is the action of the 

 pollen on the egg-cell of the same flower. 



269c. Cross -fertilization is the action of pollen upon the pistils 

 of another flower. The term is often restricted to fertilization be- 

 tween flowers upon different plants, although this is unwarranted. 



2S9d. Pollination is the act or fact of conveying the pollen, 

 whether by bees, wind, man, or other means. 



270. The simplest means by which cross -fertili- 

 zation is enforced is by dichogamy, or the different 



