250 State Horticultural Society. 



Another interesting and comparatively new line of study is that 

 of plant disease which is a botanical study in more senses than one. 

 The most destructive diseases are almost without exception caused 

 by parasitic plants of low organization. The blight of the pear and 

 apple is attributable to the growth of certain bacteria which destroy 

 the trees while feeding upon the starch contained in the young growth 

 made by them. To barely enumerate the rusts, smuts, mildews and 

 rots of our most valuable plants would prove wearisome and would 

 make an appalling list. Nearly all of these are fungi. To lessen 

 their ravages we must understand their nutrition, growth and propa- 

 gation, and the varied forms in which many of them appear. The 

 grape mildew and rose mildew are no longer the dreaded foes that 

 they were a quarter of a century ago. The educated gardener of to- 

 day understands their natural history and is able to hold them in 

 check. 



The fact that they are superseded by fungus diseases much more 

 deadly should be a stimulus to further study and one which by the 

 aid of the library and able instructors may be profitably pursued by 

 the student. 



Another branch of work that I wish to mention is that of the 

 chemical laboratory. It is quite true that the plants which we see in 

 public parks and gardens are valued for their beauty and the graceful- 

 ness which they lend to the surroundings, little thought being given 

 to the active principles which they contain. 



For instance, the poppy (papaver longifolium) though its flowers 

 are beautiful to look upon, we know that in its capsules are certain 

 juices from which opium is derived. 



In all of the large botanical gardens of today you will find a 

 chemical laboratory where the active principles of certain plants are 

 distilled and much useful knowledge is obtained, which would be 

 lost were it not for the chemical laboratory. The tobacco plant 

 (Nicotiana Tobaccum) is the subject of the tender care of the botanist 

 and chemist. Many of the diseases which attack the plant can be 

 traced to chemical processes in the soil — a lack of something here or 

 an excess of something there. 



Before concluding I wish to give a brief description of the garden 

 and point out some parts that are of interest. During the summer 

 months the outside garden is the more attractive ; which, with its 

 well-kept walks and beds and ponds, presents a picture not soon to be 

 forgotten. 



In the ponds are found the sph-ndid Nymphseas, whose leaves 

 grow to be six feet in diameter and will support a weight of several 



