HIGHER AND LOWER PLANTS 277 



teid is built from simple substances, which in turn break down 

 into less complex bodies, and are again reconstructed into pro- 

 teids, or, as cellulose and other compounds, remain as the com- 

 ponent parts of tissue in higher plants, thus serving the mechan- 

 ical and physiological needs of the organism. 



Aside from the practical application of plant products to 

 dietetics, pharmacy, and the industries, it is eminently for pur- 

 poses of scientific investigation that the field of plant chemistry 

 is most promising. 



It has been suggested to me, from botanical sources, that time 

 will be unwisely expended over a detailed study of the chemical 

 compounds of plants; in this, as in mineralogy, its use as a 

 means of classification will depend upon the convictions of the 

 investigator, although it seems to me that many of the vexed 

 questions of plant development can be solved only by a full 

 comprehension of vegetable chemistry. 



It is not to be inferred that " botanists," the knights of mor- 

 phology and systematic classification, will thereby be deprived, 

 by chemists, from tilting over the floral tournament courts. 

 Perhaps in such pleasant pastimes of contest for disputed plant 

 groups this veteran army of knights- errant may at least become 

 weary, and willingly exchange the lance for the balance. 



The vegetable kingdom is so vast that the botanico- chemical 

 facts at our disposal are meagre in comparison to the data re- 

 quired, and in consequence many of the explanatory statements 

 advanced can only be considered in the light of speculation. 

 Vistas have opened most promisingly but to be cut off suddenly 

 by a limitation of these details, and I cannot urge too strongly 

 the very great importance of minute chemical research at least 

 in certain typical members of botanical groups. Without such 

 investigation a great deal of our present knowledge is worthless. 

 The changes of the chemical compounds within the cell, the 

 simultaneous appearance of two or more compounds always in 

 association, and the predominance of some one compound in 

 certain plant groups, should be seriously considered before the 

 evolution of plant chemistry be definitely approved or con- 

 demned. These facts suggest questions which must be answered 

 before a further advance can be made in plant biology. 



