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very fact that legislative measures were considered expedient to 

 effectually control insect pests of this kind, really amounts to 

 a confession of ones ignorance of successfully controlling 

 diseases without more or less stringent compulsory efforts. The 

 oldest Pest Acts we know of dealt exclusively with the control of 

 the insects mentioned. 



Soon, however, it hecame evident that there existed equally 

 grave dangers to vegetation from other sources, viz., diseases of 

 economic plants due to fungi and bacteria, Michigan appears to 



have heen the first state to adopt legislative means to effect 

 the control of a plant disease ~ Peach Yellows. This sjjate 

 passed in .the year 1375 the so called Peach Yellows' Act. 



"fith the progress of kncv/ledge, especially since it was dis- 

 covered that vegetation may he entirely freed from certain injurious 

 insects hy fumigation or dipping, the number of Pest Acts was 

 steadily increased; other countries following the same policy, 

 but mainly touching upon entomolog-ical problems. The uselessness 

 of siMlar means if applied to vegetation infested with fungus 

 diseases was immediately recognized. However, the knowledge 

 that these means were useless in the latter respect, and although 

 nO: similar preventive means were known, yet within more recent 

 times many countries began to amend their Acts with the intention 

 of including the problems arising from the prominent nature of 

 certain communicable fungous diseases of plants. It might have 

 been foreseen that their somewhat hasty action would be liable to 

 result in failure in many instances. And after some experience 



with the measures proposed against fungous diseases this mistake 

 was fully realized. This Q.uestion requires careful study of the 



