30 



there were must have received the concentrated and inordinate at- 

 tack of a relatively excessive number of codling moths and curcu- 

 lios. The conditions, therefore, were as vmfavorable as possible to 

 the success of our experiments, —or, rather, to the effectiveness of 

 the remedies. While this fact renders the results of our work in- 

 sufdcient as a guide to the remedial measures in ordinary years 

 and under ordinary circumstances, it nevertheless gives them a pecu- 

 liar value as showing what could not have been shown under other 

 circumstances, viz. : the best these remedies can do under the most 

 unfavorable conditions. 



All the applications made were repeated much more frequently 

 than would be either advisable or economical in practice, and car- 

 ried later into the season than would be either reasonable or safe, 

 the object being, as already intimated, to determine the greatest 

 possible effect under the circumstances existing. I wish, therefore, 

 especially to emphasize the fact that this paper is not to be taken 

 as conclusive upon the questions raised, but as a contribution to 

 progress on the subject, our experiments requiring to be repeated 

 at least one other year. Indeed, as a basis of a complete estimate 

 of the value of any remedial measure against the codling moth, 

 we should have an account of its effect during one year of exces- 

 sive relative abundance of the insects, another of average abund- 

 ance, and still another of unusual scarcity. This paper is a con- 

 tribution to a knowledge of the value of these remedies under the 

 first circumstances mentioned. 



The detailed results of all our experiments and observations I 

 have arranged in the form of tables exhibiting the date of each 

 experiment ; the dates when the successive lots of apples were ex- 

 amined, whether fallen fruit or that picked at the end of the sea- 

 son ; the total number of apples examined in each lot and its 

 check; the number of apples uninjured in each; and the number 

 of those injured by the codling moth, by the curculio, and by causes 

 indeterminable. Summaries have been added showing the total 

 number, in each case, injured by insects of all sorts, and the total 

 number injured in any way. Under each of these various heads 

 I have also calculated the ratios of each injury to the entire num- 

 ber of apples examined. 



The remainder of this paper will be devoted to a detailed discus- 

 sion of the principal facts presented in these tables, followed by 

 a concise summary of the main results. 



PARIS GREEN. 



The Paris green with which I experimented was bought of E. H. 

 Sargent & Co., of Chicago, having been obtained by them, as I af- 

 terwards learned, from some wholesale grocer in the city, whoso 

 name they could not give me. As analyzed by my colleague. Prof. 

 McMurtrie, it proved to be considerably adulterated, — or, at any 

 rate, contained a much smaller proj^ortion of arsenic than the cur- 

 rent statements concerning the composition of Paris green would 

 lead us to expect. The ratio of arsenic in the specimens submitted 

 for analysis was 15,4 per cent. In our practice three fourths of an 



