MALARIA 223 



pigmented ; and when sporulation takes place there are 

 a much larger number of spores grouped together — 

 namely, from fifteen to twenty, arranged round the central 

 pigment. No crescents are to be seen in either of these 

 fevers. 



In the summer-autumn tertian and quotidian fevers the 

 parasites are always smaller than the intermittent fever 

 parasites, and only the youngest forms are found in the 

 blood, and then only during the first hours after the ex- 

 acerbation, and crescents set in after the fever subsides. 



In the mosquito cycle crescent bodies are found plenti- 

 fully. On spreading a drop of blood from the mosquito on 

 a slide, and observing without staining, it will be found that 

 in five minutes or so one-third of the crescents become 

 spherical, and a short time afterwards about 5 per cent, of 

 the spheres are seen to develop fiagella. 



Surgeon -Major Eoss is of the opinion that when it 

 becomes more general to use the microscope as an aid to 

 diagnosis in all cases of fever (speaking of countries where 

 malaria is prevalent), it will be found that a very much 

 larger number of cases are due to the parasite than have 

 hitherto been supposed. Another point of importance, in 

 his opinion, is that while crescents are swarming in the 

 blood (after an attack of fever) while the patient is con- 

 valescent, and possibly to all appearance fit for duty, he 

 should on no account be allowed to return to work till he 

 has had rest and good feeding for at least a fortnight. 



Examination of the Blood for the Parasite. — Surgeon-Major 

 Eoss recommends the examination of fresh blood without 

 drying or staining, and warns against trying to obtain too 

 thin a film by pressing the cover-slip on the slide, as there 

 is then a danger of causing some of the corpuscles con- 

 taining parasites to burst, so that they then appear as free ; 

 this is particularly likely to happen in the summer-autumns. 



