14 ORIGIN OF CULTIVATED PLANTS. 



of which the cultivator takes no note, because they are 

 useless to him. We may expect, therefore, to find the 

 fruit of a wild fruit tree small and of a doubtfully 

 agreeable flavour, the grain of a cereal in its wild state 

 small, the tubercles of a wild potato small, the leaves of 

 indigenous tobacco narrow, etc., without, however, going 

 so far as to imagine that the species developed rapidly 

 under cultivation, for man would not have begun to 

 cultivate it if it had not from the beginning presented 

 some useful or agreeable qualities. 



When once a cultivated plant has been reduced to 

 such a condition as permits of its being reasonably 

 compared with analogous spontaneous forms, we have 

 still to decide what group of nearly similar plants it is 

 proper to designate as constituting a species. Botanists 

 alone are competent to pronounce an opinion on this 

 question, since they are accustomed to appreciate differ- 

 ences and resemblances, and know the confusion of 

 certain works in the matter of nomenclature. This is 

 not the place to discuss what may reasonably be termed 

 a species. I have stated in some of my articles the 

 principles which seem to me the best. As their applica- 

 tion would often require a study which has not been 

 made, I have thought it well occasionally to treat quasi- 

 specific forms as a group which appears to me to corre- 

 spond to a species, and I have sought the geographical 

 origin of these forms as though they were really specific. 



To sum up : botany furnishes valuable means of 

 guessing or proving the origin of cultivated plants and 

 for avoiding mistakes. We must, however, by no means 

 forget that practical observation must be supplemented 

 by research in the> study. After gaining information 

 from the collector who sees the plants in a given spot 

 or district, and who draws up a flora or a catalogue of 

 species, it is indispensable to study the known or probable 

 geographical distribution in books and in herbaria, and 

 to reflect upon the principles of geographical botany 

 and on the questions of classification, which cannot be 

 done by travelling or collecting. Other researches, of 

 which I shall speak presently, must be combined with 



