LECTURE II 



INTRODUCTORY 



THE reference in the last lecture to Caesalpino's crude 

 ideas on physiology leads me to draw your attention to 

 a matter of considerable importance, viz. the gradual 

 evolution of the different aspects or departments of 

 botanical knowledge. At first, as we have seen, botanical 

 treatises were purely utilitarian horticultural, agricultural, 

 or medical, and the arrangements of the subject matter 

 were devised primarily for convenience of reference. 

 When plants began to be regarded as subjects of study 

 for their own sakes and not merely as sources of drugs or 

 as articles of food, an instinctive feeling was awakened 

 that they must be related in some way to each other, in 

 other words that they could be classified, but the problem 

 was what was to be the basis of this classification. A 

 division into herbs, shrubs, and trees was manifestly 

 unsatisfactory, for the least observant botanist of the 

 sixteenth century could not fail to notice that. a tree like 

 a laburnum had the same kind of flower and fruit as a pea, 

 a pronounced herb. One way was to fix arbitrarily on 

 some one organ as a distinguishing mark, and hence we 

 meet with systems, such as those of Lobelius, where the 

 criterion of affinity is the leaf, or of Caesalpino, where it is 

 the seed and fruit. Some botanists, as we shall find later 

 on, did not commit themselves to such artificial methods 

 of classification, and yet seemed to content themselves 

 with groping blindly after relationships, evidently hoping, 

 like Micawber, that " something would turn up." That 



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