ElGHTELiNTH ANNUAL MEETIXG. 59 



senitcs. w liicli are i)r()perly called internal poisons, because they 

 destroy the pests by being taken internally. Among these, 

 Paris Cireen and arsenate of lead are the best, with the latter 

 being in greater favor owing to its adhesiveness and freedom 

 of injury to foliage. It can be safely used not only on such 

 fruits as apples and pears, but also on smooth hard fruits, like 

 grapes and plums, for the Grape-berry Moth and Plum Curcu- 

 lio. and also even upon cabbage for the Cabbage Worm, and 

 on tobacco for the Tobacco Worms. These elements are 

 mentioned to show that while they are fundamental and have 

 been known for years by our practical horticulturists, there 

 are a few progressive steps, such as the recently demonstrated 

 use of the commercial lime-sulphur washes and arsenate of 

 lead, which enter into the subject and mark steps of recent 

 progress. 



It becomes necessary for the successful plant grower not 

 only to have a knowledge of the principles of the application 

 of fungicides and insecticides and the advancement in each of 

 these, but he must also know just what to spray, when to spray, 

 how to spray, and with what to spray. Practically each 

 kind of insect and each kind of disease germ is to be treated 

 distinctly in some regard. There is no possibility of a general 

 spray for everything. The man who writes to a specialist, as 

 some yet do, saying, 'T am going to spray my trees. With 

 what shall I spray them?" gives as little diagnosis for reply and 

 shows as little knowledge of the subject as would a person in 

 writing to a veterinarian by saying, 'T am going to doctor my 

 live stock. With what shall I treat them?" The specialist 

 answering the inquiry should know the kind and age or size 

 of the trees to be sprayed, the kinds of pests infesting them, 

 and the kind of apparatus which the owner will have at hand. 

 He will then prescribe according to the conditions. 



The horticulturist now recognizes that insects have their 

 different life histories or life cycles. There are fully as many 

 insects present on the earth and alive now (during the win- 

 ter ) as there were during their more active season of last 

 summer, but the difference is that they are at present dor- 

 mant or quiet. The successful horticulturist must know 



