174 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL.84 



(4) The teaching of entomology in ail of the State universities and colleges 

 and the consequent coming of many specialists and many workers. 



(5) The description of many thousands of species. 



(6) The publication of studies of the life history and ecology of a great 

 number of forms. 



(7) Careful work on the physiology and pathology of a number of insects. 



In agricultural entomology the advance has been, in a general way, 

 as follows : 



(i) The institution of research work in economic entomology at practically 

 all of the State Agricultural Experiment Stations. 



(2) The growth of the Federal service from a single worker to a body of 

 about 300 trained men working with a large annual appropriation which in 

 1925 exceeded $2,500,000. 



(3) The passage of the so-called Hatch Act which resulted in a Federal 

 appropriation by means of which an Agricultural Experiment Station was 

 started in each State in the Union, practically every one of them demanding 

 the immediate services of an economic entomologist. 



(4) The forming of the American Association of Economic Entomologists, 

 an organization which brings together the 600 or more workers in this field and 

 which, through its committees, watches closely the trend of investigation, and 

 which, through its regional meetings keeps the workers closely in touch. 



(5) The discovery of many new insecticides and improved means of applying 

 them, such as hydrocyanic-acid gas, the oil emulsions, the different arsenicals, 

 spraying machinery, dusting machinery, the use of the airplane in arsenical 

 dusting, paradichlorobenzene, and many others. 



(6) The development of the study of natural control, especially by the intro- 

 duction of parasites for the control of imported pests. 



(7) The development of the idea of variations in crop methods to reduce or 

 prevent insect damage. 



In medical entomology (a branch of the subject which has come to 

 the front in the last 30 years) some of the American contributions 

 (aside from the discovery by Theobald Smjth of the carriage of 

 Texas fever of cattle by a tick, the discovery by Reed, Carroll, and 

 Lazear of the carriage of yellow fever by a mosquito, and the dis- 

 covery by Ricketts of the carriage of Rocky Mountain spotted fever 

 by a tick) have been as follows: 



(i) Publication by the Bureau of Entomology of a bulletin giving the biology 

 and classification and remedial treatment for American mosquitoes, elaborating 

 control measures especially (1898). 



(2) Publication of a much larger book on the same subject (1901). 



(3) Publication of a large, four-volume monograph of the mosquitoes of 

 North and Central America and the West Indies (1912-1917). 



(4) Publication of several bulletins by the Department of Agriculture and 

 of a large book on the house fly as a carrier of disease. 



(5) Extensive experimental work carried on against malaria in the delta 

 region in Mississippi as a study of the economic bearing of malaria under 

 plantation conditions. 



