144 OSTRICH-FARMING IN SOUTH AFRICA. 



unsatisfactory ; that the true road to success is in 

 studying tlie habits and requirements of his birds, and 

 endeavouring to the utmost of the means he has to 

 supply their every want ; and, when he sees them 

 falling off in condition and spirits, to change their 

 pasture or their food. 



Many doctors and scientific men do not attach very 

 great importance to the presence of parasites in mam- 

 mals, but all admit that aves are subject to sweeping 

 epizootic diseases directly caused by entozoa, and that 

 their presence does not necessarily prove that the bird 

 was previously diseased ; and that, contrary to what 

 would have been expected, the herbivorous and gramini- 

 vorous birds are more subject to outbreaks than the 

 insectivorous or carnivorous birds. 



