THE NATURE OF HUMAN TICK-FEVER 
125 
clot has become almost black, and is placed at the apex of a slight, colourless 
weal, bordered by an ecchymotic zon° about a millimetre and a half in 
width. 
It has been S3id that ticks bite most frequently between the toes, in 
the axilla., etc. Our experience indicates that they bite, indifferently, every 
part of the body. 
Often, while still feeding, the whitish secretion of the Malphigian tubes 
is passed from the anus. At the same time clear fluid, in fairly large 
quantities may ooze intermittently from between the bases of the first and 
second pairs of legs. We have never seen fluid exude from any other situa- 
tion than this ; yet, in spite of careful search — no sections made — we have 
never been able to find any trace of an opening. 
Spirochaetes have never been seen in this fluid. 
In coitus the male lays hold of the posterior margin of the female, and, 
turning on his back, crawls forward, beneath the female, until the genital 
pores are in opposition. Pairs are often found and remain for hours in coitu. 
The productivity of the females is certainly increased by large feeding. 
The number of eggs laid at a time seems to vary greatly. Dissection shows 
that only a few eggs are mature at one time : ovipositing therefore goes on 
slowly. On two occasions ticks have been seen to be ovipositing during 
three days. In each instance only seventy eggs were laid. Our ticks were 
frequently disturbed, and for this reason, perhaps, the eggs have been 
usually found in small groups of ten or twenty. Females kept apart for 
observation have, however, been found to lay from ten to twenty eggs at 
intervals of from one to two weeks. The largest number of eggs laid at one 
time was 139. The females have sometimes, but by no means always, died 
while, or after, ovipositing. 
The eggs adhere to one another as they are laid, and look, under a low 
power, not unlike bunches of glistening, golden-brown grapes. Their cover- 
ing is soft, smooth, and highly refractile. Their shape is slightly ovoid, the 
average dimensions being 881. r 72 by 776.376 m . The largest egg measures 
959.4 by 841.32 a., and the smallest 767.52 by 664.2 jj.. In sandy soil the 
eggs may be deposited either upon or beneath the surface. The average 
temperature and the average humidity for the three months during which we 
have had ticks under observation have been as follows: — 
Tempekatukk 
Humidity 
Percentage o? Saturation 
Maximum 
Minimum 1 
6 o'clock 
i 1.45 o'clock 
12.4s o'clock 
1904 
December 
29 - 6° C 
I 97° 
c 
9+ 
76", 
190; 
January 
32-3- C 
'9-5° 
c 
95 
71-5 
7+ 
February 
29-9- C 
20'i° 
c 
9+ 
7 2-l 
Under these conditions eggs take but twenty days to hatch ; the shortest 
period noted was eighteen, and the longest twenty-three days. Occasionally, 
for no apparent reason, a quarter, or even more, of a batch of eggs has 
failed to hatch. 
