Sometimes the whole tree should be luirned to prevent contagion spread ing from it to healthy trees.
There are some plant diseases that so far have baffled all attempts to discover their causes. They are well exemplified by the peach yel which distorts and discolors twigs. leaves, and fruit of the peach. Such of these troubles as have been proved contagious and incurable should be given heroic treatment. A ffected trees should be dug out and burned. Some of the worst of these diseases seem to he due to some defect of a physiological nature, i. e.. they are plainly not caused by the germs of any outside organism.
The of ices. The spraying of plants originated in Europe, it has reached its highest development in America. From the rude heath whisk that was first used to apply Bordeaux mixture to the ;Tine vines in France, a long line of •nnprovements has led up to the great steam spray pump, with tank holding hundreds of gallons of liquid, and its hose and nozzles which send a fine spray through and through the top of a great tree. The perfected spray pump, under the control of an experienced operator, coats the leaves and stems with a film of the liquid, wasting little, and doing the work in an incredibly short time. But even with fine machinery, the success of spravin,e•
depends on the man. lie must mix his preparations properly. In order to know what lie is spraying for, and when to spray, lie must understand something of the life history of the insects and fungi lie is trying to combat. lie must know their vulnerable points. and he must strike them at the proper moment. The typical orchard sprayer is a barrel pump, in a wagon drawn by two horses. Usually one man drives and pumps while two other men direct the nozzles and deluge the rows of trees on either side.
The ,prayi fly of ,'harle owl Orpanwntal Trees. As a rule shade trees are so much taller than fruit trees that the barrel pump will not force the spray high enough. The typical spraying outfit for avenue trees is therefore a small steam or gas enejne, which throws a jet eighty to one hundred feet high, costs more than the aver age fruit grower can afford. Park commissioners are introducing and making popular the practice of spraying city trees. We may expect that in the near future cities and towns NA-ill protect their street and dooryard trees with as much care as the fruit grower now bestows upon his orchard trees.