INTRODUCTION 6 



In addition to these observers, the following individuals made volunteer col- 

 lections and observations which were transmitted to Washington: Mr. G. G. 

 Coghill, of Pacific University, Forest Grove, Oregon ; Major William M. Black, 

 U. S. Army, Panama; Mr. H. C. Weeks, Bayside, Long Island, New York; Dr. 

 J. B. Smith, State Entomologist of New Jersey, New Brunswick ; New Jersey ; 

 Dr. Alfredo Duges, of Guanajuato, Mexico ; Dr. J. W. Dupree and Prof. H. A. 

 Morgan, of Baton Eouge, Louisiana ; Dr. Jose H. Pazos, of San Antonio de los 

 Baiios, Cuba ; Dr. W. E. Britton, State Entomologist, New Haven, Connecticut. 



The material brought together during 1903 was verj' encouraging, and many 

 of the reports of the paid observers were full and contained many new contribu- 

 tions to the knowledge of the earl}' stages of mosquitoes. 



With the opening of the season 1904 it was thought best to limit the number 

 of paid observers working in the manner described above, and only tAvo were so 

 employed, namely, Mrs. Maurice F. Picker, of Big Fork, Montana, the wife of 

 Professor Picker, the head of the summer biological station at that point, and 

 Mrs. Hinds, of Victoria, Texas. Dr. A. Siegrist, of Puerto Angel, Pochutla, 

 Oaxaca, Mexico, was also tentatively engaged. The sanitary officials of the 

 Panama Canal Commission promised assistance, and two of them were promised 

 compensation for expenses incurred in collections and observations. The results 

 from Panama and from Puerto Angel were, however, nil. 



The extreme importance of a most thorough knowledge of everything con- 

 nected with the yellow-fewer mosquito (A'edes calopus) induced the grantee of 

 the research fund during the spring and summer of 1904 to mal<:e an especial 

 effort to determine its geographical distribution, and to learn as much as possible 

 about its habits. In the course of another investigation he went to south Mexico 

 in the spring, going as far south as Oaxaca, and studied the effect of altitude 

 upon the distribution of the species from the seaboard at Vera Cruz up to 

 Orizaba. The Mexican sanitary authorities were consulted, and his efforts were 

 very intelligently seconded through the great courtesy especially of Dr. Eduardo 

 Liceaga, the president of the Superior Board of Health of the Republic of 

 Mexico. 



Beginning with the middle of June, Mr. Herbert Barber, of Washington, was 

 sent upon a trip to determine, if possible, the line of northward distribution of 

 the yellow-fever mosquito in the United States. He began at Brownsville, 

 Texas, and followed approximately the line of distinction between the upper and 

 lower austral life zones as laid down by Merriam. He proceeded gradually as 

 far as Louisville, Kentucky, where the work was taken up September 1 by Mr. 

 T. H. Coffin, who followed it through to the Atlantic seaboard. 



By the operations just described the main portion of the mosquito fauna of 

 the principal inhabited regions of the United States was rather fully worked 

 up, and during 1905 an especial effort was made to secure material representing 

 the mosquito fauna of southern Mexico, Central America, the West Indies, and 

 Alaska. The Canal Zone was again left to volunteer observers. One of the 

 authors, Mr. Knab, left Washington the end of May, visited Key West and 

 Havana, then Vera Cruz, Cordoba, Orizaba, Santa Lucrecia, Rincon Antonio, 

 Almoloya, Tehuantepec, Salina Cruz, and Acapulco in Mexico; Acajutla, San 



