40 EXPERIMENT STATION. [Jan. 



melon blight (Altenmria), celery blight {Cercospora), apple 

 canker (tSphwropsis and JSectria), and winter killing of rasp- 

 berries and roses, sycamore twigs, privet and others. 



The unusually severe infection from aphis caused a loss of 

 foliage to many trees. A peculiar mottling of chestnut leaves 

 which were thickly covered with honey-dew was noticed, and- 

 examinations of the leaf tissue revealed a partial plasmolysis 

 of the cells, accompanied by considerable defoliation ; but after 

 showers, which would wash off the honey-dew, the defoliation 

 would cease. 



The general deterioration of shade trees which has been 

 noticeable for the last six or seven years has been even more 

 pronounced the last two years. The trees showing the most 

 deterioration are the elm, maple, white and black ash, butternut 

 and Norway spruce ; and the sycamore showed winter killing 

 of the twigs last season, with a Gloeosporium infection of the 

 foliage. The roots of the elm, maple and oak are constantly 

 dying back, and for the last two years maples have been show- 

 ing what is termed ^' staghead," supposed to be due to a dimi- 

 nution of water in the soil in some cases, and in others winter 

 killing of the roots is no doubt a contributing factor. Many 

 thousands of maples have been so affected in the northeastern 

 United States. Last Avinter was one of the worst on record 

 for depth of freezing, and vegetation in general was in poor 

 condition, owing to the drought, to enter upon even a mild 

 winter. The freezing of gas and water pipes was of so fre- 

 quent occurrence as to cause an unprecedented number of leaks. 

 In one city with about 50 miles of pipes, over 200 leaks were 

 recorded, the loss of gas amounting to about 33 per cent., and 

 in some cases sections of the supply had to be cut off. Thus it 

 is not surprising that winter injury of various kinds occurred, 

 although to what extent vegetation has suffered we cannot 

 tell as yet. 



