398 
Biology of Ticks 
Females. Of 28 9? under observation, one was lost, one was torn loose by 
accident, and 26 became engorged. Of these four were killed and preserved, 
leaving 22 of which six yielded normal progenies, seven yielded eggs few of 
which hatched, five laid eggs that did not hatch, whilst four died without 
ovipositing. 
That females will not as a rule attach them’selves in the absence of males 
was observed by Lounsbury (see Nuttall, p. 414). The females settle down to 
feed near males, and usually after 2-8 or more days, they wander about, as 
I have found, in search of anchored males which seize them as they approach. 
Females may seek two males in succession, but one male usually suffices. 
Females feed slowly in the absence of males. The rate at which females 
become engorged varies even when they are paired. From the time when 
they show the first naked eye signs of feeding, it usually takes 4-5-6 days 
before they drop off fully gorged, but this period may be prolonged to 19 or 
more days 1 . The female swells gradually so that she appears successively 
“■J,” “J” or “J-gorged” (as recorded in the protocols), whereas the fully 
gorged condition is reached rapidly. A female may imbibe as much blood 
in a few hours, prior to dropping off, as during several previous days. She 
usually drops off promptly when fully gorged, but there may be a delay of 
24 hours or so possibly owing to difficulty in releasing her mouthparts. 
II. HYALOMMA AEGYPTIUM. 
The general biology of this species has been considered in previous papers 
(1915-16, Parasitology , vi. pp. 105-110; vn. p. 436). 
The adults (Lot N. 1305) used in the following experiments belonged to 
the same strain used in my earlier observations ( loc . cit.). They were fed upon 
a hedgehog as nymphs, and emerged as adults on 3-6. vii. 1914. There were 
some hundreds alive after being kept unfed at room temperature for 208 days. 
A number of these ticks were placed upon the ram’s scrotum as follows: 
Day recorded 
in protocol $ $ 
On 27. i. 1915 1 8 8 (9 6 was lost) 
17 — 1 (? 9 to replace 9 6) 
The following record relates therefore to 8 dd and 8 9? and their behaviour 
upon the host on successive days: 
Records relating to H. aegyptium Males Nos. 1-8. 
1. Days 1-122 fixed, i.e. the male never moved from his first point of attachment in the right 
inguinal space outside the bag. Only one female escaped from the bag during the experiment, 
attaching herself in the opposite inguinal space. 
2. Days 1-29 fixed, though a 9 attached herself close by; between 30th and 133rd day he 
altered his anchorage slightly on three occasions, moving 11, 4, and 4 mm. respectively. 
1 Lounsbury (Nuttall, p. 418) saw females remain as long as 25 days attached to the legs and 
feet of goats. He attributes these differences to the varying blood supply obtained by the tick in 
different situations upon the host. 
