MALARIA 163 



or smaller number of spores by lines which have a radial arrange- 

 ment and give the whole an appearance resembling that of a 

 marguerite daisy. These are only found when a rigor is 

 imininent. 



Crescents are found in the aestivo- autumnal form of malaria ; 

 they are crescentic bodies with rounded " horns," and contain a 

 ring of pigment granules in the centre. They cannot be mistaken 

 for anything else, and if a single one is found it affords conclusive 

 proof that the patient has been infected with malaria. 



Films for staining are made in the ways already described, and 

 must be thin and perfect. They may be fixed by any of the 

 methods we have recommended, the alcohol-ether and the alcohol- 

 formalin methods being perhaps the best. They may be stained 

 by Jenner's stain, or by eosin and methylene blue used separately : 

 the parasites are stained pale blue and the corpuscles bright red. 



A simpler stain is that recommended by Rees {PmctMoner, 

 March, 1901), involving the use of carbol thionin, prepared by 

 dissolving 1-5 grammes of thionin in 10 c.c. of absolute alcohol 

 and 100 c.c. of a 5 per cent, solution of carbolic acid. This is to 

 be kept for at least a fortnight, and diluted with four times its 

 bulk of distilled water immediately before use. Staining is com- 

 plete in about ten minutes. Ordinary carbol thionin answers 

 very well indeed. Thionin stains the red corpuscles a faint green, 

 nuclei blue, and the parasites an intense purple. 



In a suspected case of malaria the search should not be 

 abandoned in less than half an hour, or, in the case of an 

 inexperienced observer, much longer. 



A fuller description of the parasite and the differences between 

 the forms which are present in the various forms of the disease 

 is beyond the scope of this work. 



EXAMINATION BY CULTURAL METHODS 



This is a much more difficult matter. The difficulty arises 

 from the abundant bacterial flora of the skin ; unless the most 

 thorough antiseptic precautions have been taken the results are 

 absolutely useless. They are worse than useless — they are mis- 

 leading. A case of ulcerative endocarditis, for example, might 

 be due to streptococci, but might be attributed to staphylococci on 

 the strength of an inadequate bacteriological examination. For 



