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NOTICES OF NEW BOOKS. 



Yearbook of the United States Department of Agriculture, 1899. 

 Washington : Government Printing Office. 



The Government of the United States of America is to-day 

 a greater scientific publisher than that of any other State in the 

 world. Its voluminous Reports are also scattered with the 

 greatest generosity in every scientific centre, and though the 

 term " exchange " is used, the actual debit must be largely on 

 the side of our American cousins. We have just received the 

 above, consisting of 880 pages, strongly bound and beautifully 

 illustrated, and though of the greatest importance to the agri- 

 culturist, its zoological information is not inconsiderable. In 

 noticing three contributions only, it must be understood that 

 they appertain to our special studies, and are for that reason 

 selected. 



" Some Examples of the Development of Knowledge con- 

 cerning Animal Diseases " is the title of a contribution by Mr. 

 D. E. Salmon. This paper is necessarily largely pathological, 

 but it is a full and excellent resume of the evolution of scientific 

 methods and discoveries; while its estimate of the earlier theories 

 as structures without stability, representing " the individual 

 workings of the philosopher's mind rather than the truths of 

 nature," will apply to much thought of the present day. 



"Progress in Economic Entomology in the United States " 

 is the subject of a paper by Dr. L. O. Howard. At the beginning 

 of the present century the United States, with its population of 

 only 5,000,000, and its restricted husbandry, suffered compara- 

 tively little from the attacks of insects on its crops. But now 

 the conditions are vastly altered. Increased cultivation has been 

 accompanied by a multiplication of plant-eating insects ; many 

 pests have been imported ; and now, as " the century has grown 

 older, the need of remedies against insects has grown greater." 

 The State has not, however, neglected its duties. " During the 



