Report of the President 79 



model of the Flea, the carrier of the plague bacillus from rat 

 to rat and from rat to man. This model is 120 times natural 

 size and was prepared by Mr. Ignaz Matausch of the Depart- 

 ment of Preparation. The history of the bubonic plague is 

 illustrated by a series of historical maps and photographs, and 

 the principal species of rats and squirrels which harbor the 

 plague bacillus are shown, with models illustrating modern 

 methods of controlling them. Material has been obtained for 

 a habitat group of the California Ground Squirrel, the most 

 important carrier of the plague bacillus in this country, and 

 this exhibit is now almost ready to install. 



The section of the exhibit dealing with the House Fly is 

 nearly complete, including exhibits illustrating the life history 

 of the insect and its breeding places and the methods by which 

 city and country can be kept relatively free from the fly 

 nuisance. 



A series of interesting insects and other arthropods, car- 

 riers of tropical diseases, have been placed on exhibition, 

 among others the tsetse flies, carriers of sleeping sickness; 

 the ticks, responsible for the spread of African tick fever 

 and relapsing fever, and the bugs which carry Chagres fever 

 in Brazil. For these specimens we are indebted to the British 

 Museum, the United States Public Health Service, the Divi- 

 sion of Entomology in the United States Department of Agri- 

 culture, the Texas Agricultural College and the Instituto 

 Oswaldo Cruz of Rio de Janeiro, Brazil. 



We have made a beginning with the section of the exhibit 

 dealing with the mosquito and have installed among other 

 things a series of pictures of Reed, Carroll, Lazear and Agra- 

 monte, the discoverers of the mosquito transmission of yellow 

 fever, a map showing the distribution of malaria in its relation 

 to river valleys in Arkansas and other models and maps 

 dealing with mosquito breeding and mosquito control. 



During the autumn it seemed to the department that it 



might be of interest to prepare an exhibit dealing with military 



__..-. ,. hygiene to illustrate the terrible toll taken 



Exhibit of _/* ... . ., 



..... ,.„ . by disease in military campaigns in the 



Military Hygiene J « , . / /, & 



past and the methods used for guarding 



armies against such mishaps at the present day. The case, now 



