53 * 
at which malaria was introduced into various districts, and of the 
effects which followed this introduction. Up to the present our 
information is very slight, being confined to such instances as the 
invasion of Mauritius by malaria in i 860 . 
There is also a pressing need for an investigation into the moral 
and intellectual characteristics prevalent in highly malarious districts, 
and a comparison of them with those of neighbouring parts, under 
similar economic and political conditions, but untroubled by malaria. 
This is another unworked field for historians. I take it that the 
effects of malaria are threefold : 
(1) It may kill, or drive away, the inhabitants. There is 
evidence that the population of Greece gradually declined, and 
that an inferior race, but one relatively immune to malaria, 
supplanted in course of time the older population. I hope to 
publish this evidence shortly. 
(2) It may cause physical and mental degeneration by 
making childhood unhealthy. 
(3) It may cause inactivity by punishing over-exertion and 
fatigue. 
The first thing to do will be to collect material, and for some time 
I have been impressing upon anthropologists the necessity of 
observing the psychological peculiarities of peoples among whom 
malaria is endemic. It is probable enough that the lapses into 
barbarism which so often disgrace Europeans living in tropical 
countries are at least partially caused by this disease or its sequelae. 
I am told that German officials are forced by' the Government to 
tan 7 quin ’ ne w * th them when they set out for malarious regions of 
Afiica, and the reason assigned is that moral deterioration may follow 
malaria unchecked by prophylactic measures. Unfortunately, I have 
icon unable to discover from written evidence whether this is correct 
CONCLUSION 
is certain that both Greece and Italy' were, at least in their 
lobl important centres, highly malarious during the period of their 
. ^ ht ther Athens and Rome were malarious when they were 
f J n * ,<>VVCr anc * g rea tness it is impossible to state for certain, 
a jj ^ 1 sea sc was in all probability rare, even if it was present at 
the other hand, the decline was in both cases accompanied 
