44 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 12 



secretions are often very powerful and that some of those known are 

 of very definite value. 



Probably the greatest series of advances in this science have been 

 made in the louse investigation and as a direct result of the proving 

 that the most dreaded diseases of the armies, typhus, relapsing fever 

 and trench fever, were louse transmitted. We will not discuss the 

 louse problem as such but rather bring out some of the new principles 

 which it has given entomology. Nuttall's great series of monographs 

 on the human lice, recently published in Parasitology, cover the gen- 

 eral subject verj^ well. 



There are a number of army principles more or less understood and 

 perhaps not even set forth on paper which have actuated much of the 

 work done on this subject. In this war everything has been handled 

 on a scale far surpassing anything ever dreamt of before. We have 

 had to think in millions and not in units. We have had to test each 

 proposed method of insect control in terms of universal availabiUty, 

 and maximum effectiveness. Because of the immensity of the prob- 

 lems, scientists of many branches have contributed wonderful results 

 to our new entomological science. We owe immeasurable credit to 

 doctors, sanitarians, chemists, engineers, manufacturers and to the 

 ordinary man of the street. All the brains of the nations of the world 

 have been focused on winning the war, and one of the vital elements 

 therein was the health of the great armies facing each other. There 

 have been many valuable contributions from various sources on the 

 control of the louse. 



It is an army maxim that materials and methods already in use in 

 some part of the army, and therefore more or less available, must be 

 adapted to meet as many phases of army life as possible. New prob- 

 lems must be handled if possible with materials at hand. The army 

 sanitarian must learn to shift for himself and get results without in- 

 troducing too much that is new. He must be able to get results by 

 rough and ready methods. A given unit of machinery or transporta- 

 tion must have its various capabilities for use tested to the utmost. 

 The more uses a chemical has the better. Materials usually wasted in 

 former wars are now carefully studied with the possibility of utilizing 

 them. Waste must be reduced to a minimum. Methods, materials, 

 mechanisms must be standardized and must be readily available. 

 Theoretical knowledge is of Uttle value, results count. Everything 

 must submit to the cold proof of results. Inventive genius which can 

 transmute ideas into practical working propositions stands high at 

 present. 



Now let us see how these principles have governed the cootie inves- 

 tigation and also some of our other entomological sanitary problems. 

 We should put them to use in all our future entomological work. 



