1G0 Fertilization of Flowers. 



It virtually says to the insect, " yon serve me and I will- feed you. If 

 you will carry a part of my pollen from the anthers to the stigmas you 

 may have another part to eat and a drink of nectar besides." What 

 bee could refuse such an offer, especially Avhen to such an offer there is 

 added the use of a most beautiful dining-room in which to take its 

 meals and pleasant odors and lovely colors to attract and direct it to 

 the table of dainties. 



We have thus far treated the subject in a general way. It is neces- 

 sary to be more specific. There are two kinds of fertilization. Self- 

 fertilization is the term employed to indicate that the pollen and the 

 stigma to which it is applied are produced by one and the same plant. 

 Cross-fertilization indicates that they are produced by different plants 

 of the same species. 



It would be natural to infer that self-fertilization takes place in all 

 plants that bear either perfect or monoecious flowers, and that cross- 

 fertilization is reserved for dioecious plants only. It has been found 

 that this is far from being the truth, that many contrivances and 

 structural peculiarities exist in perfect and monoecious flowers whereby 

 cross-fertilization is secured. Professor Darwin, the eminent scientist, 

 advanced the fundamental principle that nature abhors perpetual self- 

 fertilization. By his investigations he not only established the truth 

 of his proposition, but by long and patiently-conducted experiments he 

 also found that cross-fertilization was, as a rule, far better for the 

 plant than self-fertilization. He found that the descendants from 

 cross-fertilized ancestors grew more rapidly, attained a larger size, had 

 a more healthy and vigorous appearance, resisted drought, cold, exces- 

 sive moisture and the encroachments of rival plants better than the 

 descendants of self-fertilized progenitors. They also generally sur- 

 passed the others in the number, weight and productiveness of their 

 seeds. Such a result might have been anticipated by any one who had 

 carefully observed the numerous contrivances and curious floral struc- 

 tures whose evident design is to favor or secure cross-fertilization. It 

 is reasonable to suppose that such care would not have been taken to 

 effect cross-fertilization if self-fertilization would have answered as well. 



Let us consider some of the methods by which cross-fertilization is 

 accomplished. 



The simplest and most obvious means is by a dioecious inflorescence. 

 Since the stamens in this case are all on one plant and the pistils all 

 on another, it is very clear that there can be only cross-fertilization m 

 these plants. If by any chance this fails the plant is surely and hope- 

 lessly sterile. 



Closely allied to this are those cases in which the flowers are perfect 



