MOSQUITOES \.\i> m \i.\i;ia. 1 1 
place- is shorter and the infant mortality higher than in healthy 
place-. 
But, aside Prom this vitally important aspect of the subject, the 
effect of malaria in Lessening or destroying the productive capacity 
of the individual is obviously of the utmost importance, and upon the 
population of a malarious region is enormous, even under modern 
conditions and in the United State-. It has been suggested thai the 
depopulation of the once thickly settled Roman Campagna was due to 
the sudden introduction of malaria by the mercenaries of Scylla and 
Marin-. Celli, in L900, states thai owing to malaria about 5,000,000 
acres of land in Italy remain — not uncultivated, but certainly very 
imperfectly cultivated. Then also, in further example, in quite recent 
years malaria entered and devastated the islands of Mauritius and 
Reunion, practically destroying for a time the productiveness of these 
rich colonies of Great Britain and France. 
Creighton, in his article on malaria in the Encyclopaedia Britannica, 
states that this disease ** has been estimated to produce one-half of the 
entire mortality of the human race; and inasmuch as it is the most 
frequent cause of sickness and death in those parts of the globe that 
are mo-t densely populated, the estimate may be taken as at least 
rhetorically correct." 
Is it possible to make any close estimate of the ratio between the 
number of deaths from malaria and the number of eases of the same 
malady? No perfectly sound basis for such an estimate is apparent. 
In the English translation of Celli's work on " .Malaria According 
to the New l^'searches,'' published in London in 1900, it is stated 
that the mortality from malaria in Italy from 1887 to 1898 varied 
from 21,033 in the first-named year to 11,378 in the last-named year, 
and the mean mortality for the period is assumed to be about 15.000. 
In 1896 a count of the patients in the hospitals in Rome was made, 
and the mortality rate of 7.75 per thousand of the actual patients was 
established. Calculating then on this basis, and at this rate, the num- 
ber of cases per year for Italy was placed at about i\000,000. Accord- 
ing to this estimate, and with the average mortality for the United 
State- of 12,000 as above indicated, the approximate number of 
cases for the Onited State- would be about 1.550,000. It seems obvi- 
ous, however, that Celli. in using the ba>is of hospital patients only, 
must have underestimated the number of cases for the Kingdom, 
since of the people in the country suffering from malaria the propor- 
tion entering the hospital must be relatively -mail. Therefore the 
death rate from malaria of malarial patients in the hospital must be 
greater than the death rate from malaria of the- people who suffer 
from this disease in the whole country. In fact, so great must this 
u See "Darwinism and Malaria," by It. a. Eccles, M. D., Medical Record, 
New York, January m. L909, pp. 85-93. 
