Specimens of a»oplieles collected from 173 localities, in many of which malaria has never existed. Conclusion that the coincidence of the geographical distribu tion of ague and anopheles as claimed by Grassi for Italy, and probably hold ing good for other countries, is dis proved for England, and that the gen eralizations are proved to be premature whereby he excludes other blood-sueking insects from being possible hosts of 111a 1 a ria 1 parasites on the strength of this geographical concordance, and further more that the disappearance of ague from Great Britain does not depend upon the extinction of mosquitoes ca pable of harboring the parasites of ma laria. Nuttall, Cobbett, and Pigg (Jour. of Hygiene, Jan., 1901).
After feeding 57 specimens of anoph eles on a patient suffering from malaria whose blood contained crescents, 27, or 47.5 per cent., were found to be infected. These 57 mosquitoes had fed 129 times on the patient, and out of the 129 feed ings infection of the mosquitoes resulted in 46 instances, or 35.5 per cent. Man appears to be the only intermediate host of the malaria parasites. C. W. Daniels (Brit. Med. Jour., Jan. 26, 1901).
Outbreak of malaria in 'Middleburg, Zeeland, where for thirty years this dis ease had never appeared, in which the following facts were ascertained: It consisted only of eases of tertian fever, house epidemics were often observed, and it turned out that nmnerous anoph eles were found, especially where stables containing rabbits, horses, etc., were placed. Infection experiments proved successful, and, of 22 mosquitoes that had sucked blood containing gametes from a patient, the parasites were found in 18 anopheles. Van der Scheer and Van Berlekom (Brit. Med. Jour., Jan. 26, 1901).
The anopheles personally found al ways in buildings, oftenest in recently used bedrooms, and especially in the dwellings of the poor. The female be gins to bite early in March, and they have been met as late in the fall as November 6th. The time of develop ment from egg to adult is not more than nineteen days. While inoculation of anopheles quadrimaculatus with tertian parasite was successfully obtained, in fection in man from the bite of a single infected mosquito was not. The period of incubation between the bite and chill was exactly fourteen days. W. H. Berk eley (Med. Record, Jan. 26, 1901).
There is no proof that the adult mos quito is able to survive the rigors of winter in a state of hibernation, and that, as generally thought, when the season becomes warm turns active, lays eggs, and so provides for the perpetua tion of the species.
From observations made—the extreme prolongation of the larval stage and the power shown by the larvm to withstand low temperatures—it seems reasonable to infer that it is really the larvte that provide for the continuation of the spe cies through winter in these northern countries, and probably throughout Europe. It is during winter that one may hope to do most toward extermi nating mosquitoes. Larvm could be searched for and found with greater ease than those mosquitos that are said to hibernate in out-of-the-way corners.
Kerosene-oil is a most efficient larvi cide. The usual directions are that the oil should be applied and renewed from time to time. This intermittent applica tion, however, is not right. Better re sults would follow by suspending a vessel containing the kerosene-oil over the water, and arranging for the dis charge of oil a drop at a time, the out flow being regulated so that there would be a continuous film of oil on the sur face of collections of water near dwell ings that cannot either be drained oft' or filled in. M. J. Wright (Brit. Med. Jour., Apr. 13, 1901).
Successful experiment on self, as a re sult of the bite of mosquitoes infected in Rome on a case of benign tertian ague. The first symptoms of a double tertian fever appeared after an inotba tion period of between ten and sixteen days and lasted four days, when the presence of the parasite was fully ascer tained. P. Thurburn Manson (Brit. Med. Jour., July 13, 1901).
In a native Indian population in a malarious region, while the adults may be perfectly free from the disease, an enormously- large percentage of the young children contain the parasites in their blood. Though the disease ap pears to he much less dangerous to the native children than to new arrivals, implying that they have a degree of con genital immunity, the parasites in the young natives are perfectly able to cause dangerous fever in white people, when conveyed to them by mosquitoes. Hence the important practical inference that white people settling in a malari ous tropical region should not, as they now commonly do, plant their houses near native settlements, but place them at some considerable distance from them, about a quarter of a mile being apparently sufficient. Lister (Indian Aled. Record, July 17, 1901).