THE STUDY OF PLANTS IN ANCIENT AND MODERN TIMES. 19 



that the great questions connected with the phenomenon of life will be solved, 

 and to correct, on the other, the habit of not appreciating impartially the various 

 methods which have been and are still employed by difierent botanists. In our 

 own time, adhering as we do to the principle of the division of labour, it has become 

 almost universal for each investigator to advance only along a single, very narrow 

 path. But owing to the fact that one-sidedness too often leads to self-conceit, the 

 lines of study followed by others are not infrequently despised, just as overweening 

 confidence in the infallibility of the discoveries of the present day leads to deprecia- 

 tion of the labours of former times. 



For the building up of the science of the Biology of Plants everything relating 

 to the subject has its value, and is capable of being turned to account. Whether 

 the materials are rough or elaborated, massive, fragmentary, or merely connective, 

 howsoever and whensoever they have been acquired, they all are useful. The study 

 of dried plants made by a student in a provincial museum, the discoveries of an 

 amateur regarding the flora of a sequestered valley, the contributions of horticul- 

 turalists on subjects of experiment, the facts gleaned by farmers and foresters in 

 fields and woods, the disclosures which have been wrested from living plants in 

 university laboratories, and the observations conducted in the greatest and best 

 of all laboratories— that of Nature herself — all these results should be turned to 

 account. Let us take for the motto of the following pages the text: 



'Pi'ove all things; hold fast that wliich is good." 



