8 HATCH EXPERIMENT .STATION. [Jan. 



eased forms occupies considerable time. Very frequently 

 some of the diseases prove to be new, or at least little 

 understood, and a study of them must be made for the 

 purpose of gaining an accurate knowledge of their charac- 

 teristics and habits, and thus enable us to treat them in 

 an intelligent manner. It is highly important that the 

 nature of every plant disease be fully understood before 

 any attempt is made to treat it. Any attempt at treat- 

 ment not based on knowledge is as unscientific as it is 

 impracticable. Among the apparently new diseases occupy- 

 ing our attention at present are bacterial diseases of the 

 strawberry and orchid, a begonia leaf disease, a stem dis- 

 ease of the cultivated aster and a rust on the blackberry. 

 Besides these, observations are being made on a number 

 of other more or less known fungi. 



In connection with the study of injurious fungi, numerous 

 tests are being made with new fungicides, especially with 

 solutions which can be used in the greenhouse. These tests 

 are first made directly on the spores in the laboratory, and 

 then the solutions are applied to susceptible or diseased 

 plants in the greenhouse. By means of such tests the 

 efiects of the solution on the spores can be readily observed, 

 and tlie strength of the solution required for spraying can 

 be tolerably well determined. 



Nematode Worms. 



No class of plants is more frequently sent in during 

 the winter than greenhouse cucumbers affected with these 

 worms, which completely riddle the tender tissues of the 

 roots, much to the detriment of the plants. No satisfactory 

 remedy has as yet been found, though various experiments 

 are now being made in the greenhouse for the purpose of 

 relieving the market gardener from these "pests. 



Beneficial Fungi (^Mycorhiza) . 



It has been known in Europe for some years that the 

 roots of many plants are covered with fungous growths, 

 the predominance of which — in some instances, at least — 

 is believed to have some boarino; on the absence of root 



