l6o DISEASES AND INSECT ENEMIES. 



course, that we are dealing with plants in a differ- 

 ent way from what they are as we find them in the 

 open air, where they are dependent on water, air, 

 heat, and light as furnished by nature. Under 

 glass man can not only do much toward getting 

 just the plant he wants for the conditions he has, 

 but can approach the problem from another direc- 

 tion and provide the conditions best for his plant. 

 Let us make this point perfectly plain, for few 

 growers appreciate it or realize the real power be- 

 hind it. Theoretically it will be understood that 

 if the needs of the plant and the environment were 

 exactly balanced, perfect growth would result. 

 Going further, it will be seen that if just the right 

 conditions could be furnished at all times, and 

 the plant through its adaptability were able to meet 

 them exactly, growth would not only be perfect, 

 but life itself would be continuous. We cannot, 

 of course, reach this ideal, but we can strive to ap- 

 proximate it, and this is the gist of all that we have 

 said in previous chapters on soil, watering, feeding, 

 propagation, selection, etc. ; so that when it really 

 comes to discussing the diseases there is little ad- 

 ditional to say, except to describe the way the 

 plant behaves when diseased and to point out the 

 best line of action in order to once again restore 

 the equilibrium existing between the plant on the 

 one hand and environment on the other. 



The really important diseases of the violet are 

 comparatively few in number, and in the order of 



