110 DRAGON FLIES VS. MOSQUITOES. 



Mr. H. Hammond (Science, Vol. VIII., page 436) says : 

 "In 1839, during a yellow fever epidemic in Augusta, 

 Georgia, no cases originated at Somerville, a neighboring 

 suburb, among the sand hills. There Avere no mosquitoes 

 at Somerville, which was approached by a rather circui- 

 tous route from Augusta. Some years after, a straight 

 broad road was built through the swamps directly to the 

 sand hills ; cisterns were also built ; and mosquitoes ap- 

 peared and became an intolerable pest. During the yellow 

 fever epidemic of 1854 a number of cases originated at 

 the sand hills abounding with mosquitoes." 



I think that, while it may be true that the mosquito as 

 well as other predaceous Diptera can carry germs of 

 yellow fever, it would be rather a strained and unreason- 

 able complaint to urge that they are the sole causes of 

 that epidemic. These instances, however, emphasize the 

 noxious character of the mosquito and make the inquiries 

 and suggestions of Dr. Lamborn of very essential value. 



Again, the mosquito has been accused of further mis- 

 chievous activity in spreading entozoic diseases. Accord- 

 ing to the researches of Drs. Mason and Cobbold (P. Lin. 

 Soc, pages 304-311, 1878, and Trans. Linn. Soc. Loud., 

 2 ser., Vol. II., page 367, 1884) and others, it appears 

 certain that these insects disseminate the parasite Filaria 

 sanguis hominis by absorbing them into their system 

 when imbibing the blood of their prey, and afterwards, by 

 their death, contaminate drinking waters into which they 

 fall with these entozoa imprisoned in their bodies. Sonsino 

 in Egypt (Med. Times and Gaz., May 13, 1883, page 

 494, and Sept, 22, page 340, 1883) and Lewis in India 

 (14 Rep. Sanit. Com, India) have both confirmed Mason 

 and Cobbold statements as to the entrance of Filaria into 



