210 KEPOET OF THE COMMISSIONER OP AGRICULTURE. 



whole country. The case is parallel to that of a localized contagious 

 disease among animals, and I would recommend it to your careful con- 

 sideration. 



Several other subjects are treated of in the Report, but no insect occu- 

 pied quite so much attention during the year as the Periodical Cicada. 

 Two extensive broods of this insect appeared, and in view of the interest 

 in the subject I have thought it worth while to discuss it at somelengtli. 

 I have, therefore, under various subheads, given some statements ni 

 well-known facts, together with a number of observations and some e.\ 

 i«eriments unrecorded prior to the present year. I would especially ciili 

 i!ic attention of the reader to the map illustrating the distribution vi 

 I he two broods and to the summary of the chronological history of all the 

 dili'erent broods known, and will be thankful for any data from any cor 

 respondent in reference to the same. 



On the whole the season has been one of marked activity in certain 

 special directions, and the routine work of the Division has greatly in- 

 creased. The amount of the r(tutine work may be gathered from the fact 

 that over 7,500 letters have been received and answered during the year, 

 exclusive of answers to circulars sent out. Some new lines of investi- 

 gation have also been begun. Chief among these is that pertaining to 

 economic ornithology. 



The work of this Division touches intimately on various other branches 

 of zoology, but on none more than on ornithology. Few injurious insects 

 can be well and fully considered without reference to their liability to 

 be devoured by various natural enemies, and especially birds. The in- 

 terrelation between birds and insects is a theme which necessarily inter- 

 ests any one who fully appreciates all the bearings of applied entomology, 

 and I have for some time desired to take up the subject as part of the 

 work of the Division. How complicated these relations are is rendered 

 obvious by the excellent work done in this line by Prof. S. A. Forbes, 

 State entomologist of Illinois, and by Mr. F. H. King, in his report on 

 economic relations of "Wisconsin birds, made under the direction of the 

 geologist of Wisconsin. 



Hitherto these investigations have been undertaken either by private 

 individuals or under State aid. Last winter the American Ornitholo- 

 gists' Union, a body organized some two years ago, petitioned Congress 

 to appropriate means for such investigations by tlu^ National Govern- 

 ment, and an appropriation of $5,000 was finally obtained, and this Di- 

 vision charged with carrying on the investigation. The chief interest 

 which the farming community has in this work is in reference to the 

 food-habits of birds, though the inquiry will cover all questions of an 

 economic nature relating to North American ornithology, and especially 

 bird migrations and geographic distribution. In planning the work I 

 have taken charge of that part relating to food-habits, because of its 

 intimate entomological bearings; while Dr. C. Hart Merriani, aidcvl Ijy 

 Dr. A. K. Fisher, will take charge of all the other pluises of the in(inir\ . 



For the last two years the American Ornithologists' Union has math' 

 bird migration and geographic distribution the subject of s])ecial inves- 

 tigation, and has secured the voluntary services of some foui teen hwu 

 dred observers. Dr. Merriam, as secretary of the Union and chairman 

 of the committee on migrations, has been able to secure the services of u 

 large number of these observers in the Department work. Much is thus 

 gained by co-operating with said Union. The work was begun only on 

 the 1st of July, and no formal report of re.sults has yet been prepand, 

 as the gathering of material and the examination of birds' stomachs 

 necessarily involve a great deal of preparatory labor. A bulletin on 



