4 NATURAL SCIENCE [July 
organic injury it causes. But not a word of explanation on these 
points was given by his opponents. Dr Sambon attributed the 
mortality of the tropics to three diseases—dysentery, haematinuria, 
and malaria. These are, undoubtedly, due to specific organisms 
which are especially prevalent in the tropical zone, but are not 
necessarily connected with the heat. If the existing white mor- 
tality and the past degeneration of races long subjected to the 
effects of these maladies are simply due to them, then there is good 
hope for the future. Dr Manson cited the case of that most 
repulsive of diseases, elephantiasis, which was once one of the 
terrors of the tropics, and was then charged to the climate. 
But Manson has shown that elephantiasis is due to the organism 
known as Milaria ; he has worked out the life-history of the parasite, 
and shown how it enters the human body. People being thus 
warned have only themselves to thank if they now contract 
elephantiasis. This case gives us good hope that, when the life- 
histories of the haematozoa of malaria, dysentery, and haematinuria 
have been similarly worked out, the diseases will be brought 
similarly under control. That is the hope for the future, and what 
is wanted is more knowledge of the biology of the parasites. Malaria 
is now being admirably studied by the medical schools of Rome and 
Vienna. Haematinuria is the most obscure and deadly of African 
diseases, and it will continue to entail on England lamentable 
sacrifices of life and money until it can be dismissed as Manson 
has dismissed the fear of elephantiasis. Most of the doctors who 
find their way to our African tropical protectorates are medical 
sportsmen and not medical biologists. They probably could not 
focus a high-power microscope if. they tried. An institute for the 
study of tropical diseases is urgently needed, and would pay as a 
policy of imperial insurance. 
For THE LADY CYCLIST 
In the June number of the Scottish Medical and Surgical Journal, 
Dr J. W. Ballantyne gives a valuable digest of forty-five papers that 
have been written on bicycling for women. On the whole it appears 
that the advantages, from a physiological point of view, wholly 
outweigh the disadvantages, if these be guarded against by proper 
precautions. These latter are chiefly associated with the choice of a 
machine, the essential point being that the seat should be suitably 
placed and adapted to the anatomy of the female pelvis. “It should 
be pretty well forward, and when the cyclist is erect in the saddle 
her heels should touch the pedal when lowest, her feet being in the 
horizontal position. The commonest faulty position is having the 
saddle too low and too far back; on the other hand, the saddle too 
high is also wrong, causing over-stretching of the knee and ankle, 
