51 
one present, it is rareh^ properly cared for: furthennon* it is the excep- 
tion rather than the rule that it is used. As a result uncinariasis is 
widespread, not because the country air is particularly favorable to 
its develo])iuent, but simply because so little attention is paid to the 
proper disposal of the focal discharo-es. 
SYMPTOMS ARE MOKE SEVERE IN SIMMER THAN IN WINTER. 
It is almost universally conceded that the patients are in better con- 
dition in winter than in summer. Accordino- to testimony, the .symp- 
toms begin to increase in the spring and to decrease in the early winter. 
This periodicity will be noticed, of course, only in localities which are 
above the frost line, and it is easil}’ explained when we take into con- 
sideration the biology of the parasites. Cold retards and heat hastens 
the development of the eggs and the embryos; a freezing temjierature 
of 2d to 48 hours' duration, it is said, kills both ews and embrvos. 
Accordingly, after frost sets in in the fall, the })atients will add less to 
the infection which is present in their bowels than they will during the 
summer. Some of the worms already in the intestine will be jiassed, 
thus decreasing the number of parasites present; the patient will 
accordingly lo.se less blood and will on this account feel somewhat 
better. As warm weather begins in the spring the free eggs and 
embryos will develop more rapidlv and the infection will he increased. 
There will be more parasites in the intestine, hence symptoms will be 
augmented. 
Some few patients, however, insist that they are better in summer 
than in winter. 
It is probable that the seasonal periodicity of the symptoms noticed 
in our Southern States will be moditied in the Trojiics, so that the 
.s3’mptoms will increase in severit}^ in the rainy season and decrease in 
the drv period of the year. Such a periodicitv would corresjunul to 
the liiologic fact that the eggs and embrvos perish very qiiicklv upon 
becoming diw. 
In patients who are not subject to continued infection, as for 
instance those who have left the area of infection, the sc'asonal 
periodicitv may be expected to disappear. 
WIIITE.S AI’PEAK TO BE MORE SEVERELY AFFEtTED THAN NE<iROt>i. 
Osier and other observers havealreadv noticed that chlorosis is mure 
freijiient in blondes than in brunettes. 
Uncinariasis occurs in both blondes and brunettes, and in liolh the 
white and the negro, but .so far as mv observations go tin* disease is 
more severe, liaf<f more mdietahh^ in blondes than in brunettes, 
and much more severe, as a rule, in the white than in tin* negro. I his 
observation was sup])orted l>v all the (*vidence I could gather from 
local pln’sicians. In fact, .several jiractitioni'rs declared that thev had 
never seen a case in the negro to recognize it. riiere is, however, 
abundant evidence that such cases do occur. 
