154 NATURAL HISTORY ESSAYS 



results, though genuine horse-sickness blood has 

 been found to contain certain bodies, both inside 

 and outside the blood corpuscles. Little is known 

 as to their true nature, but it appears that neither 

 forms can be readily stained with the aniline dyes 

 usually employed in microscopic examinations, 

 and that the extra corpuscular bodies exhibit great 

 variations in size. Hitherto the only chance of 

 recovery has been afforded by the rough and ready 

 treatment of bleeding the equine patient to ex- 

 haustion : Oswell tells us that he succeeded in 

 saving one or two horses by this risky method.^ 



The tse-tsef\y {G/ossina morsitans) was originally 

 brought to the notice of Europeans by Oswell 

 and Vardon, who met with it on the Siloquana 

 hills near the Limpopo ; the first specimens 

 brought to England being those caught by Vardon 

 on his favourite horse. Many specimens have 

 since been received in this country, and may be 

 seen in the principal museums. The tse-tse is 

 about the size of a house-fly, and is greyish-brown 

 in colour, the abdomen being gaily striped with 

 yellow. This insect is thus very much smaller 

 than the absurdly-exaggerated figures of it in 

 books would lead one to suppose : it is misleading 

 to compare the tse-tse to a bee in size, as is often 



1 The late Roiialeyn Gordon Gumming once •prevented his horses 

 from taking this distemper by preventing them from eating gi'ass, and 

 by covering them at night with blankets — the former precaution 

 alone would probably have been sufficient. 



