THE ORGANS OF REPRODUCTION. 5 1 



but with the dispersal of plants by various natural agencies to 

 new localities, bringing them into association with new plants 

 and with new animal friends and foes. All these changes, neces- 

 sitating changes in the habits of plants, taken in connection 

 with the well-known tendency of plants to vary, have led to pro- 

 found modifications in their structure. The descendants of 

 plants which were alike, have come to differ from each other 

 and from the parental forms ; from a few kinds, an immense 

 number of species and varieties have arisen. 



In the course of the adaptive changes which plants have 

 undergone, the organs of reproduction have, of course, also 

 undergone much modification; but here conservatism is more 

 evident, especially as respects the essential organs of the flower, 

 and changes in them have taken place more gradually than 

 in other parts of the plant. The habits and appearance of 

 related plants may have undergone profound change, while the 

 flowers still bear a strong resemblance to each other in essential 

 points of structure. The Elm and the Nettle, for example, are 

 as different as possible from each other in size and in habits of 

 growth, yet the record of their close relationship is preserved in 

 their flowers. 



It is for these reasons — because of the light which flowers 

 throw on the relationships of plants, and the clews they give us 

 to the history of their descent — even more than on account of 

 the appeal which beautiful flowers make to the aesthetic sense, 

 that they command the enthusiastic interest of botanists. 



It must not be inferred from this, however, that the scientific 

 study of a flower in any way dulls the enjoyment of it as a thing 

 of beauty. It is a foolish, though very popular, error to suppose 

 that this is the case. It would be scarcely less absurd to sup- 

 pose that the less one knows of art, the more he will enjoy a fine 

 picture or a fine statue. Surely, in the study of flowers, as in 

 every other worthy subject of knowledge, our enjoyment of them 

 will increase as we understand them, and it will be measured by 

 the extent and thoroughness of our knowledge of them. 



But we must guard against the error of supposing that in 

 studying the organs of reproduction, we are studying entirely 

 new ones. They are, in fact, the old vegetative organs, changed 

 for the purpose of adapting them to new functions. The " leaves 



