MOSQUITOES AND MALARIA. 9 



the valley of the Po and elsewhere. The introduction and spread of 

 malaria in Greece is stated by Ronald Eoss, and with strong reasons, 

 to have been largely responsible for the progressive physical degen- 

 eration of one of the strongest races of the earth. 



In the United States, malaria, if not endemic, Avas early introduced. 

 The probabilities are that it was endemic, and it is supposed that the 

 cause of the failure of the early colonies in Virginia was due to this 

 disease. It is certain that malaria retarded in a marked degree the 

 advance of civilization over the North American Continent, and 

 particularly was this the case in the march of the pioneers through- 

 out the Middle West and throughout the Gulf States west to the Mis- 

 sissippi and beyond. In many large regions once malarious the disease 

 has lessened greatly in frequency and virulence owing to the reclama- 

 tion of swamp areas and the lessening of the number of the possible 

 breeding places of the malarial mosquitoes, but the disease is still 

 enormously prevalent, particularly so in the southern United States. 

 There are many communities and many regions in the North where 

 malaria is unknown, but in many of these localities and throughout 

 many of these regions Anopheles mosquitoes breed, and the absence 

 of malaria means simply that malarial patients have not entered these 

 regions at the proper time of the year to produce a spread of the 

 malady. It has happened again and again that in communities where 

 malaria Avas previously unknown it has suddenly made its appearance 

 and spread in a startling manner. These cases are to be explained, 

 as happened in Brookline, Mass., by the introduction of Italian labor- 

 ers, some of wdiom were malarious, to work upon the reservoir; or, 

 as happened at a fashionable summer resort near New York City, by 

 the appearance of a coachman who had had malaria elsewhere and 

 had relapsed at this place. In such ways, with a rapidly increasing 

 population, malaria is still spreading in this country. 



To attempt an estimate of the economic loss from the prevalence 

 of malaria in the United States is to attempt a most difficult task. 

 Prof. Irving Fisher, in one of his papers before the recent Inter- 

 national Tuberculosis Congress, declared that tuberculosis costs the 

 people of the United States more than a billion dollars each year* 

 In this estimate Professor Fisher considered the death rate for con- 

 sumption, the loss of the earning capacity of the patients, the period 

 of invalidism, and the amount of money expended in the care of the 

 sick, together with other factors. In making these estimates he had 

 a much more definite basis than can be gained for malaria. The 

 death rate from malaria (as malaria) is comparatively small and is 

 apparently decreasing. Exact figures for the whole country are not 

 available. From a table comprising 22 cities it appears that two- 

 thirds of the deaths from malaria in the United States occur in the 

 South — one-third only in the North. The death rate from malaria 

 83434— Bull. 78—09 2 



