386 THE AGRICULTURAL JOURNAL. 



That flies might prove the bearers of 

 the contagion from the eye of one animal 

 to another is possible, but purely con- 

 jectural, especially when one considers 

 the habit of the ordinary Muscas, and 

 their quiescence during the time which — 

 by the strongest weight of evidence — is 

 looked upon as the most dangerous. 



To complete the brief survey of this 

 theory there remains the question of the 

 possible agency of Intestinal Parasites, 

 which are probably never absent in the 

 South African herbivora, but are always 

 to be demonstrated by careful inspection 

 of the intestinal contents. 



The frequency with which the larvae of 

 the CEstrus Equi (Bots) are noticed in^-ios'- 

 mortem reports of the disease should not 

 remain unnoticed in view of the manner 

 in which the integrity of the gastric mem- 

 brane is affected by these parasites. No 

 confirmatory evidence, however, exists in 

 this case, either pointing to the probability 

 of such a factor obtaining in the etiology 

 of South African Horsesickness. 



Upon a consideration of the various 

 theories as set forth above, the evidence of 

 the greatest weight seems to lie in favour 

 of what I have termed the Inoculation 

 Theory. All the features of the disease 

 most difficult to understand seem recon- 

 cilable to a greater extent to this theory 

 than to others mentioned. While much 

 work has been done in the past it is pro- 

 bable that still more remains for the 

 future. In my own researches into this 

 disease, meagre as th%y have been, and 

 hedged about by many limitations, I have 

 sought rather to probe into the difficulties 

 surrounding the cause of the disease than 

 to devise means for its actual cure or pre- 

 vention, believing that the quickest way 

 of establishing the Prevention upon a 

 sound basis lies primarily in the recogni- 

 tion of its Cause. The difficulties in the 

 path of the enquirer are unusually great, 

 seeing that no organism is discoverable, 

 and that the actual mode of production of 

 the disease is equally obscure. Another 

 serious difficulty — appreciable only by 

 those who have undertaken research work 

 of this nature — is that the malady is prac- 

 tically untransferable to other animals 

 than those of the Equine species. Were 

 it possible!] to produce the disease in 

 guinea-pigs or rats, or other easily obtained 

 find inexpensive animals, there is no doubt 



that the investigation of the disease would 

 be much lightened. Horses, on the other 

 hand, are procurable only after difficulty 

 and expense, and it may be that the very 

 economy which it is imperative to observe 

 in conducting an investigation to any ex- 

 tent leads to the use of the class of animal 

 not the most suited, by reason of age and 

 environment, to the enquiry in hand. 



As far as I have been able to judge 

 the endeavour directly to prevent or cure 

 the disease has met with so small a 

 measure of success as to be unsatis- 

 factory, and I am at present of the 

 opinion that no preventive inoculation 

 is likely to give permanent satisfactory 

 results. 



To those who are impatient for 

 practical results I would refer to the 

 labours of such men as Koch and Pasteur, 

 where many years of assiduo us labour in 

 solving the problem of eradicating an 

 obscure disease has met with but partial 

 success. 



Koch is to-day, in the light of a mature 

 and unique scientific experience, labour- 

 ing, with every facility at his disposal, 

 at the disease tuberculosis, and as we all 

 know, his work is far from complete. 

 Unlimited lime, extended knowledge, 

 much expense, aud great thought, are 

 necessary to the undertaking of an inves- 

 tigation into an obscure disease, and the 

 prospects of success in such work are not 

 heightened when able and experienced 

 men of science have already thoroughly 

 exploited the field, and found it " stale 

 and unprofitable." 



The future, however, for the horse- 

 owner, and particularly for the horse- 

 breeder, is not a hopeless one. Investi- 

 gators have already accumulated a mass 

 of evidence — much of it negative in 

 nature, but still valuable, about the 

 disease horsesickness, and progress is C(m- 

 tinually being made towards a successful 

 solution. In conclusion, I would ask the 

 Natal agriculturist to briefly review in 

 his mind the possible causes of the 

 disease which I have laid before him, 

 and bring to bear upon them his past 

 experience. 



Many have already written to me their 

 opinions on the subject, some dissenting 

 but many concurring with my inclination 

 toward Inoculative Theory, as being the 

 most probable solution of the difficulty. 



