M.— AGRICULTURE. . 231 



Indeed, it seemed as if little progress had been made since the fourth 

 century after Christ when the Greek writer, Chiron, maintained that 

 glanders and similar diseases were caused by the ' pestiferous hot southerly 

 wind from Africa.' 



However, great strides were made during the latter haU of the nine- 

 teenth century. The work of Louis Pasteur and Robert Koch cleared up 

 the aetiology of some of the most important infectious diseases. And the 

 later researches of David Bruce, Adolphe Laveran, Theobald Smith and 

 others, added further brilliant chapters to our knowledge. 



Since the beginning of the present century the growth of Veterinary 

 Science has been phenomenal. In every branch of this science there have 

 been remarkable developments. Indeed, it may be said that a New 

 Veterinary Science has arisen unobserved by the general public. A quarter 

 of a century ago the veterinarian was looked upon as a moderately useful 

 though obscure member of the community, whereas to-day he is regarded 

 as an essential factor in the economic machine of the State. A generation 

 ago the value of a veterinarian was judged by his ability to cure a lame 

 horse or an ailing dog ; to-day the veterinary profession is judged by 

 the measure of success which attends their efforts to keep their country 

 free of epizootic diseases. Formerly the work of the veterinarian was 

 individual, to-day it is national. 



In this transformation of Veterinary Science the British Dominions and 

 Colonies played no unimportant part. The veterinarians who had 

 migrated to those countries and taken with them the stock of knowledge 

 which they had obtained at the European veterinary schools, found 

 themselves confronted with new problems which required solution. 

 Research work on a large scale became necessary. Novel methods of 

 attacking disease had to be devised. The farmer soon came to realise 

 that his very existence depended on the protective measures devised and 

 enforced by the veterinary staffs. 



I propose in the short time at my disposal this morning to review 

 briefly some of the most notable achievements of Veterinary Science in 

 recent years, and to indicate how the work of the veterinarian has become 

 interrelated with that of workers in other branches of science. 



It will be convenient to divide our subject into sections and to quote 

 a few examples from each of these. 



Let me begin with the largest and most important field of work of the 

 veterinarian, viz. : — 



A. Animal Diseases. 



And let me group this subject according to the aetiology of the various 

 diseases : 



1. Trypanosomiases. 



Probably no other single group of disease-producing organisms has 

 retarded the agricultural development of the continent of Africa more 

 than that of the trypanosomes. If the cattle population of Africa be 

 estimated at about 40 million head, it is quite safe to say that this number 

 could easily be doubled if the danger of trypanosome infection were 

 removed. In Nigeria, for instance, only a portion of the drier Northern 

 Provinces is suitable for cattle ranching ; the much more fertile Southern 



