44, THE AUSTRALIAN NATURALIST. 
and houses the fleas that infest them are as deadly as a black 
snake. With the knowledge thus gained thousands of pounds 
have been spert in Sydney in making rat-proof floors, and 
the constructien of wharves in which rats cannot take shetter, 
for without rats there are no rat fleas. 
Fleas are also strongly suspected of spreading that living 
death—leprosy—in the same manner, and this would account 
for the rapid and mysterious way in which this disease has 
spread in such countries as Hawaii, where at the Lazaretto 
at Molokai Island there are some 1400 lepers, including all 
ranks and races, men, women and children. The South 
American Jigger is another flea that has the unpleasant habit 
of burrowing under toe nails of the natives, where the female 
flea rapidly increases in size, she lays her eggs and produces 
ulcers that often incapacitate the natives from walking. This 
flea has been accidentally introduced into tropical Africa, 
and quite recently an exploring expedition had to make a 
halt, as all the carriers were suffering from ‘Jiggers.”’ 
Though not true insects the Ticks should be noticed and 
while not going into the question of the great losses caused 
by the disease —Redwaté¢r—transmitted to cattle by the 
Queensland Cattle Tick, we find others that produce similar 
diseases in man. 
Drs. Dutton and Todd shewed that the blood parasite 
Spirillum of relapsing fever of Africa was transmitted from 
man to man by the bite of the African tick (Ornithodoros 
moubata.) Not only does this tick while sucking the blood 
of a fever-stricken man become infected but it passes the para- 
site on te its eggs and larvae, so that the next generation of 
ticks are virulent and capable of reproducing relapsing fever 
without further contact with fever-stricken man. 
Spirillum fever, the spotted fever of the Rocky Mountains, 
. Karapath disease of the Zambesi, and the fever in Persia and 
Beluchistan are all caused by micro-organisms transmitted 
by ticks. 
Many brave, earnest workers have laid down their lives 
in carrying out the investigations that have thrown so much 
light on the mysterious tropical diseases, and through finding 
the cause, have enabled the authorities to take measures that 
have checked yellow fever, malarial fevers, plague, and sleep- 
ing sickness, saving the lives of countless thousands. All 
honour to the heroes of science like Dr. Dutton of the Liver- 
pool Tropical School of Medicine, who contracted relapsing 
fever in Africa while working at this disease, Dr. Walter 
Myers who contracted yellow fever and died at Para, Lazear, 
who died during the same investigations, Young Manson ac- 
cidentally killed in one of the Liverpool Tropical School Ex- 
peditions and a host of other well-known men. 
