168 I.8.C. Proceedings of the Ninth |N.S., XVIII, 
with some degree of precision the period during which prophyian™s 
measures, such as the use of mosquito nets, are necessary in any g 
Finally, with a ttre of the climatic and other factors concerned 
in the mechanism of epidemic omnes it should become possit-le to fore- 
ast the occur eks 
and it may well be that the time is not far distant when ‘‘ epidemic fore- 
cunts > will become a normal function of the modern epidemiologist. 
(4). Conclusion. 
The views briefly advanced in this paper suffice, I think, to i pe 
that climate exercises a marked influence in the causation of malar 
cere 
course not the only factor concerned ~ ae mechanism of 
sadder gis but it seems justifiable to conclude that climatic conditions 
constitute a — = importance itis both Aheeudec sa to neglect and 
difficult to over-r 
Mee does oo seiaie of the consideration of the — role of os 
a cme 
mate in the causation of other epidemic di oo sigt n t suffice 
stale that whilst little or no ee knowledge appea xist on the 
subject, it is not unreasonable me that the eS asta will be 
found to exercise an ana ~ gous “influence in the niger get of many epi- 
demic diseases. In the of plague, for example, it was show n by the 
Plague — feta that The severity of plague epidemics in the 
Punjab during each spring was cl osely as associated with excessive bute 
during the four months preceding their ee and it was concluded 
that this circumstance was due to the favourable effect a humidity on 
the pupa of rat-flea 
B — ts ae to have been carried out to determine the 
precise in sidcoetia of humidity on oie rat-flea or indeed on any of the 
other ‘‘ carriers " of human dise 
ex i on to this “festa a are some observations of Kinghorn — 
An 
and Yorke (1912) on the influence of termperature and humidity es the 
deve oe eycle of Trypanosoma rhodesiense in Glossina nia 
_, hese observers reached conclusions —— ree to those cae 
tailed in conan with oe transmiss of malarfa al- 
though they recorde servations 0 on ne influence sf paberg mere 
ene pool on hone life-history ‘of See fli 
: it expedient to — a S epeet ee only mer 
} Hoenes in Sibaiocs 8 b oa sect-carrier, for it is 
clear that all pathogenic caraalicn are sone the aati nce of mete 
orological conditions during their extra-c srpercat peed 
inding ere would appear therefore to be few epidemic dise ases, not 6x 
i uding holes, in which the in nifucads of the climatic ge can be safe- 
ma Alistegarded. Little or nothing appears to be known in regard to the 
Fee uence of climate me directly-transmitted epidemic or but I hope 
© show in a paper now under preparation the manner in whi ey the cli- 
matic factor is involved | in the mechanism of epidemic influenz 
i bbe these remarks I will conclude in the hope that siciont has 
deni syne to justify the view that the yuma of climate in relation to epi- 
calculate provides @ wide field of investigation whose prose ution ast 
i: 2 to throw fresh light on the piece re of epidemicity aD 
us lead to the discovery of new methods of prevention. 

