MEDICINE, RECENT ADVANCES IN. 



This was the final proof of the complete cycle Much still remains to be clonr 



through man and the mosquito. But there were means proved that there is no other 



still many skeptics, so some infected Anopheles gating the disea.se than In MIOM, 



were allowed to bite a man in Rome, and he soon though it now seems probable ih 



developed the malaria parasite in his blood. Still There is no certainty that other 



the skeptics were not satisfied the man might mosquito besides A tiophclc* may not ji.-i 



have been infected in some other way, or had a mitters of the germ. The only thin- \\c -j.-m, 



a* * lof^f i,*^, < ^ KI~^ all the time> to be fair , certi{in of iH that j non(; J f tl '; 



347 



by no 

 piopa- 



<-. ul- 

 -- t inc. 

 the 



STOMACH OF ANOPHELES. 



sort of latent infection in his 

 So finally Dr. Manson, wish- 

 ing to make the proof striking 

 and positive, devised two cru- 

 cial tests, which were carried 

 out in the summer of 1900, and 

 the results leave the fair-mind- 

 ed skeptic defenseless. 



The first of these consisted 

 in sending two physicians 

 Drs. Sambon and Low to live 

 in a very malarial district on 

 the Roman Campagna (Ostia) 

 during the most malarious 

 season of the year, their only 

 protection from the disease 

 being mosquito-netting. No 

 quinine or other prophylactic 

 was taken, and they were di- 

 rected to sleep with the win- 

 dows and doors open so as to 

 give any bad night air there 

 might be " a chance at them." This they did, species do so. There are, however, about 240 

 living in a house whose only peculiarity lay in known species of mosquito, and it is not at all 

 its being mosquito-proof. Here they stayed all improbable that some of these may be found to 

 summer, and while the whole surrounding popu- possess the same claim to distinction, and ex- 

 lation of natives was down with malaria, neither tinction, as the Anopheles tribe, 

 of the unacclimated experimenters ever showed Then the discovery has opened a new field in 

 a trace of it. This proved that unacclimated the fight against malaria by practically chang- 

 people could live in perfect health in an extremely ing it into a war of extermination against the 

 malarious region, where even the acclimated na- mosquito. This is being actively carried on in 

 lives are continual sufferers, by simply avoiding several portions of Italy, and to some extent also 

 mosquito bites. in this country. The mosquito breeds chiefly in 



For the second experiment some laboratory small bodies of surface water which contain no 

 mosquitoes were reared from the eggs in Rome, fish (fish eat up the eggs and larvae), and hence 

 pastured on a malarial sufferer there, and then especially those about new excavations. One of 

 sent alive to London. Here they were permitted the prophylactic methods now urged is the filling 

 to bite a healthy man whose blood had been 

 examined and shown to be free from the malaria 

 germ. Dr. Manson's son volunteered for the serv- 

 ice. He was bitten freely by the mosquitoes, and 



Each of the dark spots represent a malaria parasite which has grown until 

 it forms a wart-like excrescence on the stomach wall. (After Koss.) 



ONE OF THE WART-LIKE BODIES MUCH ENLARGED, 

 WHICH HAS JUST RUPTURED, AND FROM 

 WHICH THE GERMINAL RODS ARE SEEN ESCAP- 

 ING (After Boss.) 



SALIVARY GLAND OF AN ANOPHELES, SHOWING THE GERMINAL 

 RODS IN THE BODY OF THE GLAND, AND ALSO ESCAPING 

 FROM THE PROBOSCIS OF THE MOSQUITO. (After KoSS.) 



in a short time he not only developed, in the 

 heart of London, the clinical symptoms of ma- 

 laria, but his blood was found to be swarming 

 with the typical parasites. 



These two experiments complete the story, and 

 from the purely scientific point of view, as well 

 as from that of the utilitarian, few achievements 

 in modern medicine have equaled it. 



up of all such small puddles, and the covering of 

 the surface of the larger ones with kerosene 'oil, 

 which prevents the larva from getting air, and 

 hence smothers it. These two methods, with the 

 careful use of mosquito-netting, are the means at 

 present believed to be the best preventives of 

 malaria. Persons finding it necessary to go into 

 regions having a bad reputation for malaria 



