F. C. Bisiiopp and H. P. Wood 
175 
TABLE VI. The parasitic period of development of 
Dermacentor albipictus. 
1910 Infestation No. 1. On rabbit. 
Oct. 
18. 
1 1 
19 
( 1st 
day). 
1 1 
31 
(13th 
day). 
Nov. 
5 
(18th 
day). 
11 
11 
(24th 
day). 
11 
17 
(30th 
day). 
” 
19 
(32nd 
day). 
23 
(36th 
day). 
11 
27 
(40th 
day). 
Dec. 
11 
(54th 
day). 
5 1 
19 
(62nd 
day). 
1911 
Apr. 
26 
11 
27 
( 1st 
day). 
May 
5 
( 9 th 
day). 
1 1 
9 
(13 th 
day). 
„ 
20 
(24th 
day). 
11 
27 
(31st 
day). 
1911 
About 200 larvae put on head of rabbit. 
About 100 appeared to be attached. 
2 at least engorged or nearly so. 
Larvae began moulting. 
A Dympk appears fully engorged. 
The above nymph moulted to a female. 
Female crawling on host and shaken off several times, 
from host. 
Another nymph moulted to a female. 
Female lost. 
Another nymph moulted to a female. 
Female lost. No other ticks found. 
Infestation No. 2. On guinea-pig. 
About 100 larvae put on guinea-pig. 
Many larvae attached. 
1 larva appears fully engorged. 
Above larva moulted to a nymph. 
First nymph moulted (<?). 
Male scratched off by host. No other ticks found. 
Infestation No. 3. On rabbit. 
Removed 
Mar. 15, 4.45 p.m. 
„ 15, 6 p.m. 
,, 15, 9.30 p.m. 
„ 17 ( 2nd day). 
„ 27 (12th day). 
Apr. 1 (17th day). 
,, 2 (18th day). 
,, 3 (19th day). 
,, 5 (21st day). 
,, 10 (26th day). 
1911 
Oct. 24, 3.15 p.m. 
Nov. 1 ( 8th day). 
,, 6 (13th day). 
„ 11 (18th day). 
,, 15 (22nd day). 
,, 20 (27th day). 
Dec. 1 (38th day). 
„ 2 (39th day). 
,, 7 (44th day). 
,, 9 (46th day). 
75 larvae put on rabbit. 
7 or 8 attached. A few crawling. 
20 or 30 attached. 
At least 6 attached. 
2 larvae fully engorged. 
1 moulted to a nymph. 
Another moulted to a nymph. 
Smaller nymph scratched loose, later reattached. 
1 nymph is fully engorged. Other not found. 
Nymph moulted to a female. No other ticks found. Female 
removed. 
Infestation No. 4. On guinea-pig. 
75 to 100 larvae placed on guinea-pig. 
Some larvae appeared fully engorged. 
Larvae began moulting. 
3 nymphs appeared engorged. 
First nymph moulted ( $ ). Last larva moulted. 
7 males, 7 females and 2 nymphs found. First copulation ob¬ 
served. 
6 females (slightly to J engorged) scratched off the host. 5 males 
attached. 
5 females (slightly to J engorged) off the host. 
Only 1 male found. 
2 males scratched off by the host. No other ticks found. 
