PRESIDENT'S ADDRESS. Ixiii. 



man and beast. At the British Association meeting this year in 

 South Africa, a paper was read by Colonel Bruce, giving much 

 information on the various diseases of stock in South Africa, 

 connected with these organisms, and the best means of com- 

 bating them. In some cases the parasite passes one stage of its 

 existence in the body of a tick, and is thus conveyed to the 

 animal to which the tick attaches itself ; in others it is conveyed 

 by a fly. In several instances a great difficulty in stamping out 

 the disease is caused by the fact that the wild animals harbour 

 and propagate the parasites, though they do not suffer from 

 them like the domestic ones, just as the natives propagate 

 the parasites of malaria without harm to themselves. Sleeping 

 sickness and other human diseases are produced in a similar way, 

 and much progress is also being made in the knowledge of them. 

 Another difficulty in some of these diseases is that the parasites 

 cannot be discovered, and are supposed to be too small to be 

 seen by our microscopes. The parasite of yellow fever, for 

 instance, has never been seen, though there can be little doubt 

 that it exists. Many new protozoal parasites, including various 

 new species of trypanosomes, have been discovered during the 

 past year, and it is to be hoped that in time many of the 

 diseases they produce will, like malaria, be brought under some 

 control. Malta fever has received much attention in the last year, 

 two suspected causes being goat's milk and certain gnats. Even 

 paralysis has now been stated to be caused by a bacillus ; if so, 

 confirmation will, no doubt, be forthcoming. May we, v/hilst we 

 study the scientific aspect of these diseases, take a practical 

 lesson from the wonderful immunity from them, especially enteric 

 fever, enjoyed by the Japanese army in their late campaign, 

 which was entirely due to the careful attention to details of their 

 medical officers, and the way in which their instructions were 

 conformed to by the troops. 



The researches of Professor Jennings, published during last 

 year, show that even amongst these lowest living creatures there 

 are evidences of intelligence which it will be, perhaps, more easy 

 to realise when we consider that it is not so long ago that 



