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tories becomes a matter of no small importance. Then, too, the 

 structure and habits of the host plants must be taken into con- 

 sideration, for upon these may depend the means of prevention 

 or of cure. The assembling of this information and its practical 

 application to the question in hand devolve upon that type of 

 botanist usually referred to as the mycologist, and despite many 

 failures much that is of substantial practical use has been estab- 

 lished. One of the earliest, if not the earliest, recorded instances 

 of where a community has taken formal notice of the fungus 

 pests of plants is found in the old Barberry Law passed by the 

 province of Massachusetts before the Revolution. This called 

 for the extirpation of the barberry which had been noticed by 

 the colonists, without any knowledge on their part of the real 

 causQ, to be connected with the rust of their wheat fields. To- 

 day we may not pass laws for the destruction of diseased plants, 

 realizing perhaps the hopelessness of enforcing them, but we 

 combat plant disease by the establishment of experiment stations 

 devoted to the investigation of such matters. 



As a result, there is now at the disposal of the agriculturalist 

 much definite information of ways and means of diminishing or 

 preventing loss through the destruction of crops by disease, 

 losses which statistics show may amount to tens of millions an- 

 nually ; and while the study of the action of bacteria and fungi 

 in the disease of plants is by no means complete, no one can 

 deny the practical results which have been attained. In the 

 more indefinite functional diseases of plants not ascribable to 

 definite parasites, there is room for much more information, 

 which will be forthcoming when our knowledge of nutrition 

 physiology is more full. Already, however, we have sugges- 

 tions as to the cause of the functional diseases which often ap- 

 pear where the same crop has been raised for many years in suc- 

 cession in the same spot, which bid fair to explain some impor- 

 tant plant ailments that are at present not understood. 



A more popularly interesting line of activity that has a prac- 

 tical bearing is found in plant breeding, which has recently been 

 attracting wide attention. Plants are now bred systematically 

 for desired characters, not always for increased yield only, but 



