76 
Biology of Ixodidae 
having been partially emptied, the clear areas above described appear 
broader. The chitin has darkened somewhat, and the posterior portion 
of the “median plate” is clearly seen to be tegumentary (not hard) and 
pale; the hypostome and its base have now taken on a dark orange 
tint. After the fifth day the palps appear markedly darker distally. 
Whereas the tick is very sluggish in its movements during the first days 
after ecdysis, it moves about actively by the sixth day; the legs now 
appear darker and yellowish, the gut is much more contracted, and the 
stiff white hairs protruding from the posterior margin of the body^ are 
frequently seen to be soiled by black excrement which forms ink-like 
spots when voided on filter paper. The base of the hypostome is now 
reddish-yellow in colour. 
As the male ages, the body becomes concave ventrally, the pale 
areas become still broader, and the posterior part of the scutum curves 
more abruptly toward the venter so that the ventral plates project 
considerably. The distal portions of the palps and the moveable articles 
of the legs acquire a granular greenish colour especially on the ventral 
side. The yellow-coloured median plate is now seen to extend only 
two-thirds the distance between the sexual aperture and the anterior 
margin of the anal plate^. 
Female. The body of the freshly emerged female appears well 
filled, the legs pale, etc., as in the male. After 72 hours the base of the 
hypostome has acquired a distinctly orange-red tint, the tips of the 
palps are bluish, the legs begin to harden and show yellow and black 
dotted banding; although the intestine has been partly emptied it 
would seem as if the female does not void excrement as quickly as does 
the male after ecdysis. After 4-5 days the gut caeca are clearly 
distinguishable (Fig. 2 c), palpal articles 2-3 are bluish and trans¬ 
lucent, the distal portions of the articles of the legs show annulations 
having a bluish tint, the ventral surface of these articles being a 
translucent orange-yellow. This colouration of the legs is maintained 
until the tick dies. The hypostome and its base is of a bright orange- 
red colour, the spiracles are milky with a large orange-red macula. All 
1 In one of the males a malformation was observed in that the tuft of hairs was absent 
on the posterior margin of the anal plate. 
2 This is contrary to what has been described hitherto, because in preserved specimens 
the line of demarcation between the hard median plate and the membranous integument 
posterior to it is indistinct. I. futus is the only species of Ixodes at present known where 
the median plate does not cover the whole surface bounded by the ventral grooves, anal 
and adanal plates. 
