tion experiments was there a recurrence of Cronartium the fol- 

 lowing season. In our own case the outbreak on currants can not 

 be satisfactorily accounted for except on the assumption that the 

 two nearby Pin us strobus trees were diseased last spring. It may 

 be possible to determine this point next spring. If it can be proven 

 that these trees were free from Peridermium in the spring of 1906 

 then it would seem that we have here evidence in support of 

 Eriksson's view ; for it is scarcely possible that pine trees sixty 

 rods or more distant can have been responsible for so abundant 

 an infestation. 



ATTEMPT AT ERADICATION. 



In order to stamp out the disease, if possible, every Ribes plant 

 on the Station grounds has' been destroyed. The two white pines 

 standing by the currant plantation, also, will be destroyed if they 

 show the disease next spring.* A careful watch will be kept over 

 pines and currants in the vicinity of the Station and in case of 

 the appearance of the disease next season measures will be taken 

 to secure the prompt destruction of all affected plants. Perhaps 

 the disease may be stampted out, but the chances are against it. 

 The writer knows of no record of a successful attempt at the com- 

 plete eradication of a fungus disease of plants. It is rarely at- 

 tempted. 



Even should this attempt prove successful, it can not be ex- 

 pected that the disease can much longer be kept out of America. 

 Considering the frequency with which pine trees are imported it 

 is a wonder that the disease has not made its appearance here be- 

 fore. 



ITS PROBABLE IMPORTANCE IN AMERICA. 



It is improbable that growers of currants and gooseberries in 

 America have much to fear from this new disease. Even when 

 currant leaves are abundantly infested with the rust fungus they 

 appear to be but little injured by it. On the Station grounds 

 * black currants which were badly infested held their leaves until 

 well into October. 



The chief danger from Cronartium rihicola lies in its effect on 

 pine trees, particularly the white pine. In parts of Europe it 

 has wrought havoc among white pines and there is no apparent 



* These trees have not shown presence of Peridermium Strohi though ex- 

 amined carefully since 1(100. 



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