THE GREW ZEBRA 



153 



and whip of some leather-lunged Kaffir. The 

 progress of exploration and trade would have been 

 seriously hampered without such valuable auxili- 

 aries. U nfortunately, travellers are still hindered by 

 two most serious scourges the veldt-sickness, 

 which attacks "unsalted" horses, and the progres- 

 sive emaciation caused in oxen by the bite of the 

 tse-tse fly. 1 These twin plagues, which have cost 

 African travellers many thousands of pounds, are 

 not yet fully understood, but it may be interesting 

 to briefly consider them in this place. 



The horse-sickness is a non-contagious fever of 

 malarial type, produced in annual epidemics by a 

 minute fungus which grows on the veldt during 

 the African summer. Owing to its moisture- 

 loving nature, this curse is especially potent in 

 damp places and at night : it attacks grass-fed 

 horses with great virulence, over 95 % of the 

 affected animals succumbing. The equine patient 

 stands with running nose and eyes and lowered 

 head, his heaving flanks telling too plainly of the 

 impeded respiration and the rapidly-developing 

 pleuro-pneumonia which will probably carry him 

 off in a few hours : those horses which survive, 

 however, are immune from further attack. Attempts 

 have been made to investigate the hypothetical 

 germ which produces the illness, but with uncertain 



i The student will recollect the dismal fate of the early Portuguese 

 expeditions of the sixteenth and seventeenth centuries, which were 

 often ruined by the tse-tse killing all their horses. 



