FAMILY CULICID/E THE MOSQUITOES 91 



that the disease would not become established in this country, but, 

 unfortunatel}', few doctors are familiar with the symptoms of yellow 

 fever and there is grave danger of the disease remaining undiagnosed 

 until it is too late to take precautionary measures. Even though steps 

 have been taken to quarantine all persons coming from known yellow 

 fever areas the danger of introduction of the disease is an ever present 

 menace. 



Dengue or Break-hone Fever is another disease carried by the 

 Yellow Fever mosquito (Aedes aegypti). It is a common tropical and 

 subtropical disease and there are occasional out])reaks in the Southern 

 States, corresponding to the distribution of the mosquito. After biting 

 a patient it requires from eight to eleven days before the mosquito is 

 capable of transmitting the disease. 



The microfilariae of Wuehereria hancrofti Cobbold are taken up (in 

 America) by Culex fatigans Wiedemann and undergo development in 

 the muscles of the mosquito, in much the same way as described for 

 Malaria but there is no increase in numl^ers and they do not become 

 sexually mature until they have been returned to the human body. 

 The worms occur in the lymphatic system and may he responsil)le for 

 a number of organic disturl)ances. The region about Charleston, South 

 Carolina is the only area in the United Staates where Filariasis is preva- 

 lent but it is common in the tropics of both liemispheres. 



Since wi-iting the foregoing and preparing the following key, 

 Edwards' fascicle in the "Genera Insectorum" (194), has appeared. 

 In this work the Dixida? are included as a subfamily of the Culicidse, 

 a course I do not follow. An examination of this important fasicle 

 of "Genera Insectorum*' will disclose the fact that Edwards makes 

 free use of su])genera. i\Iy views on this question are expressed else- 

 where in this work. With the author's view tliat genera should be 

 limited to grouj^s readily characterized in both sexes I most heartily 

 agree. The quality of the scientific work of this author is of too high 

 a standard to warrant criticism except of a most favorable nature and 

 one can disagree with him only on questions of minor importance. The 

 question of subgenera is really one of likes and dislikes, and I prefer 

 to keep as close as possible to a binomial system of nomenclature. 



Most of the cuts used to illustrate this family are from "A Hand- 

 book of the Mosquitoes of North America" by Dr. Robert IMatheson 

 and I wish to express my indebtedness to him and to Mr. C. C. Thomas, 

 the publisher, for furnishing them, and also my appreciation of their 

 wlioleliearted cooperation. 





