482 ZEBRULES 



number of useful animals in a similar way. The zebrule is 

 not proof against the poison of the tsetse fly, Glossina 

 morsitans, but this is not to be wondered at, as the zebra 

 bred away from the fly country is not itself immune. 1 



1 For full particulars, consult The Penicuik Experiments, by J. C. 

 E wart, published by Adam & Charles Black, London, 1899; papers in 

 the Journal of the Highland Society for 1902 ; and, " The Utility of Zebra 

 Hybrids," by Thos. H. Dale, in The Transvaal Agric. Journal, 1904. 



