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deposit it in the blood of a healthy person. Those interested are 
referred to the admirable paper entitled ‘‘On the réle 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 may 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 March, 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 delivered at the Royal 
Institution of Great Britain on March 2, by Maj. Ronald Ross, D. P. H., 
M. R. C. 8., lecturer in tropical medicine, University College, Liver- 
pool, himself one of the workers whose results contributed most 
materially to the establishment of definite proof. Another recent 
account will be 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 
Heemamoebide are cultivable in Anopheles claviger 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 before 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 from 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. Cogquillett, of the office force, comprising (1) a 
1 Dr. Woldert’s article contains a good account of the internal anatomy of mosqui- 
toes and describes his methods of dissection. 
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