322 GENERAL SCIENCE 



Many of the old time orchards have been allowed to go to 

 destruction, given over to the ravages of worms .and to such 

 diseases as the fungus growth called " apple scab." For- 

 merly every home had its apple trees about the house, and 

 every farm its orchard. Now apple raising is a highly spe- 

 cialized industry employing a large investment of capital and 

 expensive outfits in machinery and appliances. It demands 

 much business ability successfully to finance, raise, and mar- 

 ket the crop. m 



The agricultural colleges of the country have done much 

 in their courses in horticulture to make possible the success 

 that to-day attends the effort to supply again to the American 

 people an abundance of apples as a most wholesome and 

 appetizing fruit. To fight successfully the insect pests that 

 attack the crops of the farmer, and the various parasitic 

 growths like the apple scab, the rust on wheat and oats, 

 and a long list of bacterial diseases, there has been rapidly 

 developed the need of a scientific education in agriculture 

 as an occupation. Biological and physical sciences as applied 

 in agriculture are an indispensable preparation for success- 

 ful farming. Instruction once gained only through expe- 

 rience on the home farm is now given as courses in 

 college. 



The material used as a spray for the codling moth com- 

 monly contains some compound of arsenic. Paris green is 

 often used. The purpose is to coat both the leaves, and the 

 fruit (preferably just after it has been formed, and shortly 

 after the blossoms have fallen) with a fine spray of the poison- 

 ous material. The larvae hatched from eggs laid by the 

 moth in the early spring are killed by feeding upon the foliage 

 and fruit. Lime when slaked is a fine white powder, and 

 when mixed with the water containing the Paris green and 

 applied to the foliage in the spray, shows by its whitening 

 effect just how evenly and completely the application has 



