SEVENTEENTH ANNUAL MEETING. 213 



this season in determining, for the first time, the midsummer history of the 

 species. For this purpose plots of wheat were sown at two points in southern 

 Illinois, at regular intervals from the middle of July to the 1st of October. 

 By watching these wheat plots from week to week he has clearly established 

 the occurrence of a third generation of the fly breeding in volunteer wheat and 

 completing its development in the fall. This observation seems to make it 

 entirely possible to keep this pest in check by such a management of the 

 wheat fields in midsummer as will bring this third brood into existence in the 

 volunteer wheat and then destroy it before sowing for the new crop. 



"Another less-known wheat insect, the wheat bulb loorm, was shown, as an 

 incident of these experiments, to be sometimes as destructive as the Hessian 

 fly and to be commonly confounded with it by wheat growers. A third brood 

 of this species also was discovered in midsummer wheat, so that the same 

 measures which will destroy the fly will apply to this as well. 



"An elaborate trial has been made of Paris green and other chemical poi- 

 sons applied to apple trees in spring, to test precisely the value of this measure 

 as a protection against the codling moth and curculios. More than 22,000 

 apples from these trees were examined, one by one, in the course of this experi- 

 ment, and nearly as many more last year. 



"Various apple-leaf bisects have lately made it almost impossible, in some 

 localities, to raise young nursery stock, the young leaves being destroyed as 

 fast as they put forth. Experiments made in the field have shown that by a 

 combination of hand picking and poisoning, used with due reference to the 

 life histories of the species, these insects may be rendered harmless at a rela- 

 tively small expense. 



"Very numerous and careful studies and experiments have been made by 

 Professors Forbes and Garman on the contagious diseases of insects, — a sub- 

 ject which has become a leading specialty of the office, systematically studied 

 nowhere else in the country, and nowhere else in the world on nearly so large a 

 scale as here. It has been demonstrated this summer that one of the most 

 destructive of these diseases may be conveyed at will to healthy insects by arti- 

 ficial means, and that it may also be thus carried from one insect species to 

 another. 



"Besides the above, a great number of minor items of information of both 

 scientific and practical value have been gathered from the field and from 

 the breeding cages of the office, altogether making up a very unusual record 

 of progress. In addition to a full detail of the subjects mentioned, the next 

 report from the office will contain an elaborate illustrated monograph on all 

 the insects known to affect Indian corn in America." 



Several questions concerning insects were presented and answered, follow- 

 ing which the general topic for the afternoon was taken up. 



SCHOOL HORTICULTURE. 



A note was read from Geo. R. Knapp, Associate Editor of the American 

 Garden, to open the discussion : 



HOW TO TEACH HORTICULTURE. 



The ennobling profession of horticulture has gained so many devotees, and 

 taken so high a standing among preferred and valued industries, that the 

 question of the best methods for its thorough promulgation has become a 



