42 



throughout, so that the water, when it issues, will be broken up into 

 streams. It will sometimes be found necessary to file the tips as they 

 come from the factory to produce the desired results. 



The spray tip proper is attached to a brass fitting, which in turn screws onto the 

 end of a three-quarter-inch hose. The apparatus is very effective for spraying roses, 

 as it readily serves to keep the leaves in a thoroughly healthy condition, and at the 

 same time wets the beds but little. It is also very useful for violets, as with a pres- 

 sure of 35 to 40 pounds the leaves of the plant can be readily turned over and thor- 

 oughly washed without soaking the crowns and the bed. In spraying some plants, 

 particularly violets, it has been found advantageous to use a lance 18 inches long, 

 made of a piece of one-half-inch brass pipe. This increases the reach, and enables 

 the operator to place the water to better advantage on plants which under ordinary 



Fig. 14. — Tip and greenhouse nozzle, complete (from Galloway) . 



conditions would be beyond arm's length. The apparatus can be made for 50 cents, 

 and will be found a useful instrument wherever there is sufficient water pressure to 

 insure a proper amount of force. (Circ. 17, Division of Vegetable Physiology and 



Pathology.) 



THE BLACK OR BROWN APHIS OF VIOLETS. 



(Rhopalosiphum viola Perg.) 



Until within five or six years from the present time one of the most 

 troublesome insects upon greenhouse violets in the vicinity of the Dis- 

 trict of Columbia, as well as elsewhere, was a plant-louse known to flor- 

 ist- as the "green fly "or "green aphis." Some time in the spring of 



