400 
Biology of Ticks 
The foregoing protocols demonstrate the following regarding H. aegyptium : 
Males. <$ 1 remained isolated from females outside the bag and did not 
shift his position during 122 days. $ 2 remained fixed for 29 days and shifted 
three times afterwards between 30th and 133rd days. <$<$ 3-8 remained 
fixed for 7, 5, 5, 4, 10, and 14 days respectively before they sought females; 
<£ 6 was lost in his wanderings. 
After a period of quiescence during which they indulged in a preliminary 
feed, the shifting about of the males was very pronounced as long as females 
were present. After the females had dropped off gorged, the males remained 
anchored within a very restricted area, shifting usually but a few mm. at a 
time up to the 139th day, except in the case of 6 which was lost after the 
14th, and $ 3 which was removed on the 64th day. 
d 5 sought two ??, the rest sought but one $, but without doubt the males 
would have each sought several females had opportunity offered. The male 
may stay but a short time with a female or he may remain several days 
with her. After the female with which a male has mated abandons the host, 
the male may either wander away or remain attached for days or indefinitely 
at the same anchorage he occupied when the female was present. Females 
brought close to anchored males caused them to become greatly excited; 
a female ($ 5) placed in the vicinity of a male, anchored herself beside him. 
Females. With but one exception the females did not shift their anchorage 
from start to finish; they were all sought by males, with the possible exception 
of $ 4, whilst, as previously stated, $ 5 was placed near an excited male. 
The male that fertilized $ 1 remained with her so short a time that the union 
escaped observation. The females did not appear to copulate with more 
than one male. $$ 2-9 dropped from the host 8, 7, 8, 5, 6, 6 days respectively 
after being approached by a male or having been seen to copulate. All of the 
females were fertilized and yielded a normal number of offspring. 
III. RHIPICEPHALUS BURSA. 
For an account of the general biology of this species, the reader is referred 
to my earlier papers (1913-15, Parasitology , vi. pp. 139-140; vn. pp. 438-448, 
457-460). 
The adults (Lot N. 1305a) used in the following experiments belonged to 
the same strain that was employed in my previous studies ( loc . cit.). They had 
emerged 9. iii. 1914. On 26. i. 1915 there were some hundreds alive after 
having been kept unfed at room temperature for 323 days. The ticks were 
placed on the ram’s scrotum in successive batches as follows: 
Day recorded 
in protocol £ ? 
On 26. i. 1915 1 11 11 
16 — 3 
18—3 
Totals 
11 
17 
