CHAPTER 1 



A CHAPTER FOR THE LAYMAN 



Vegetables are organised bodies, which extract from the 

 earth the juices proper to their nature. Vegetable substances 

 are much more compound than mineral. Their analysis is 

 consequently more difficult: certain principles, of too great 

 tenuity or volatility, escape us entirely. — Beaum^. 



Thoughtful people have always been attracted by the 

 patterned development of a plant. Practitioners of several 

 branches of science allied to agriculture now find considerable 

 interest in the topic of growth substances. 



The subject is not really new, as its beginnings can be 

 traced back to some observations of Charles Darwin, but it 

 has recently become popular with remarkable rapidity. This 

 onset of interest is possibly due less to an appreciation of the 

 importance of the subject of growth-regulation than to a 

 widening knowledge of the extraordinary results which can 

 be achieved by the use of some of the growth substances 

 lately prepared artificially. Botanists have long known that, 

 with certain plants at least, it is possible to induce roots to 

 grow from the middle of the stem of a plant, but that it could 

 not be done without some trouble. It is now easy to make 

 roots sprout on stems of almost any soft-wooded plant merely 

 by painting them with something out of a bottle. It is not 

 hard to understand why many laymen, as well as botanists, 

 have had their imagination quickened. 



This initiation of rooting on stems and leaves is something 

 more than a laboratory trick, because the same substances 

 that produce roots on leaves will cause roots to appear on 

 cuttings more rapidly than they will appear in the ordinary 

 way after putting into compost. To the horticulturist, there- 

 fore, the recent artificial preparations of growth-regulating 



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