THE ASSOCIATION OF CHARACTERS 



241 



many other characters. This cause, though hidden from 

 our eye, and showing itself only in its effects, must be the 

 real character, which by means of heredity has come to 

 be present in all members of this large family. We may 

 assume it to be pure and simple, even if it is never allowed to 

 show itself as such, but must always become visible in com- 

 bination with the other characters of the same species, and 

 may be changed by them to 

 a greater or lesser degree. 



The physiologist has re- 

 marked, however, that the 

 laws of heredity cannot be 

 the only cause of the simi- 

 larity among plants. In 

 innumerable cases there is 

 a likeness which cannot be 

 explained by a common 

 origin. The spurs of the 

 orchids and of the violets, 

 of the toadflax and of the 

 columbine are evidently the 

 same organs, playing every- 

 where the same part of pro- 

 ducing honey for the visiting insects. Notwithstanding their 

 differences in size and color, and even in the manner of 

 secreting their product, there can be no doubt as to the 

 identity of the primary cause which has produced them. 

 On the other hand the plants which bear them belong to such 

 widely divergent families, that it is simply impossible to 

 look for a common origin in order to explain this repeated 

 occurrence of spurs. 



So it is in almost every case, for characters of the high- 

 est systematic value as well as for minor marks. Inferior 

 ovaries are found among dicotyls and among monocotyls, 



Fig- 73- 



Flowers of columbine, show- 

 ing the spurs. 



