486 Canadian Record of Science. 



vent our race leading a healthy life in the tropics, is 

 due to a minute parasite which inhabits the cells of 

 the blood, and which is carried from one person to 

 another by a certain species of mosquito. If one, 

 therefore, goes to the most fever-stricken districts of 

 the tropics and avoids the mosquitoes, one can escape 

 the disease. One of my Cambridge friends, J. S. 

 Budgett, Esq., made two visits to the River Gambia 

 in West Africa in successive years. On the first 

 occasion the manner of the transmission of the malaria 

 infection was still unknown, and Mr. Budgett con- 

 tracted the disease and suffered severely from it 

 during his stay in Africa, and after his return to 

 England. On the second occasion, the mosquito had 

 been declared to be the source of infection and Mr. 

 Budgett took precautions, in fact he lived and moved 

 and had his being under a mosquito-netting, with the 

 result that he escaped the disease entirely. 



The history of this great discovery may be outlined 

 as follows : — About thirty years ago, a zoologist, 

 Lankester, discovered a parasite in the blood-cells of 

 the frog. ISTo notice was taken of his discovery at the 

 time ; but the parasite was re-discovered ten years after- 

 wards by a physiologist called Gaule, who, however, 

 being unacquainted with natural history failed utterly 

 to recognise the parasite as animal. Lankester then 

 repeated his observations and pointed out that the 

 animal, which he called Drepanidium ranarum belonged 

 to a class which had been previously studied by 

 zoologists, and the outlines at least of whose develop- 

 ment was known. When doctors, however, com- 

 menced to study malaria they were convinced that it 

 was due to a bacillus, ( that is to say, to one of the 

 minute moulds which are the cause of so many 



