18 



deposit it in the l>lood ot a health}' person. Those interested are 

 referred to the admirable paper entitled "On the role of insects. 

 Arachnids and Myriapods, as carriers in the spread of bacterial and 

 parasitic diseases of man and animals; a critical and historical study," 

 by George H. Nuttall, M. D., Ph. D., published in Volume VIII of 

 the Johns Hopkins Hospital Reports, and to later American summaries,, 

 among which ma}" be mentioned that by Dr. W. N. Berkeley in the 

 New York Medical Record for December 23, 1899, by Dr. Albert 

 Woldert in the Journal of the American Medical Association for Feb- 

 ruary 10, 1900/ and by Dr. William Britt Burns in the Memphis Medi- 

 cal Monthly for ]\Iarch, 1900. One of the most thorough of the recent 

 reviews will be found in Nature for March 29, 1900, pages 522-527, 

 entitled "Malaria and mosquitoes," a lecture deliv^ered at the Royal 

 Institution of Great Britain on March 2, by Maj. Ronald Ross, D. P. H., 

 M. R. C. S., lecturer in tropical medicuie. University College, Liver- 

 pool, himself one of the workers whose results contributed most 

 materially to the establishment of definite proof. Another recent 

 account will ])e found in the Popular Science Monthly for July, 1900, 

 by Dr. Patrick Manson, entitled "Malaria and the malarial parasite." 

 It should be stated here, however, that only the mosquitoes of the 

 genus Anopheles have been found to contain the human blood para- 

 sites, although it does not appear from the published accounts which 

 have met the writer's eye that any other genera than Anopheles and 

 Culex have been studied in this connection. 



The Italian observers have found that all three species of the human 

 HajmamoebidiB are cultivable in Anoj)heles dmriger and not only in 

 this but in other Italian species of Anopheles, while they, together 

 with Ross and other observers, have failed to cultivate the parasites 

 in Culex. The same fact is upheld by the extended observations made 

 in West Africa and in this country so far as observations have been 

 made as yet. The writer, however, wishes to emphasize the point 

 which he made l)efore the American Medical Association on June 6, 

 1900, that American physicians, especially those in the Southern States, 

 should not delay the investigation of the very large mosquitoes of the 

 genus Psorophora and Megarhinus f . om the malarial standpoint. Both 

 of these genera have been figured and described in succeeding pages. 



SYNOPTIC TABLES OF THE NORTH AMERICAN MOSQUITOES. 



In order to enable the ready determination of our different mos- 

 quitoes the writer published in Circular 40, second series, of this office, 

 in February of the present year, a series of tables, drawn up at his 

 request by Mr. D. W. Coquiliett, of the office force, comprising (1) a 



' Dr. Woldert' s article contains a good account of the internal anatomy of mosqui- 

 toes and describes his methods of dissection. 



