457 
ARTIFICIAL PARTHENOGENESIS IN TICKS. 
By GEORGE H. E. NUTTALL, E.R.S. 
{From the Quick Laboratory, University of Cambridge.) 
The occurrence of parthenogenesis in ticks was referred to by me 
in a preliminary note {Parasitology, vi. pp. 139-140), wherein it was 
stated that I had observed it in Rhvpicephalus bursa under experimental 
conditions. The following protocols relate to two attempts to raise 
the parthenogenetic offspring of several females. In both experiments 
the fed females and eggs were maintained at 30° C. until the females 
had died and the larvae had been given ample time (97-104 days) in 
which to emerge from the eggs. We failed, however, to raise the 
offspring beyond the larval stage. 
Experiment 1. 
Wherein 20 ?s (1st generation) were placed upon a ram on 18. ii. 1913. 
Only 1 ? was lost. 
No. of 
? 
No. 
No. of days 
$ stayed 
on host 
Date when ? 
dropped off 
host 
No. of 
days 
before 
ovipos. 
began 
No. of 
days. 
ovi- 
position 
lasted 
No. of 
days ? 
survived 
after 
ovipos. 
No. of 
eggs laid 
per ? 
No. of 
days 
larvae 
emerged 
after 
No. of 
larvae 
which 
emerged 
days 
sterile ? s 
lived after 
dropping 
from 
liost 
1 
25 
15. ra. 1913 
5 
17 
33 
1990 
— 
0 
— 
2 
25 
99 
4 
15 
21 
1680 
18 
2 
— 
3 
30 
20. in. 
5 
14 
29 
2160 
12 
10 
— 
4 
52 
11. IV. 
— 
— 
— 
0 
— 
— 
3 
5 
54 
13. IV. 
9 
10 
14 
1008 
9 
1 
— 
6 
57 
16. IV. 
— 
— 
^ — 
0 
— 
— 
42 
7 
57 
99 
— 
— 
— 
0 
— 
— 
27 
8 
57 
99 
9 
11 
13 
+ s 
— 
0 
— 
9 
57 
99 
8 
9 
9 
+ s 
— 
0 
— 
10 
57 
99 
— 
— 
—■ 
0 
— 
— 
70 
11 
57 
99 
— 
— 
— 
0 
— 
— 
3 
12 
57 
99 
— 
— 
— 
0 
—• 
— 
42 
13 
69 
28. IV. 
— 
— 
— 
0 
— 
— 
42 
14 
69 
99 
— 
— 
— 
0 
— 
— 
36 
15 
69 
99 
— 
— 
— 
0 
— 
— 
33 
16 
80 
9. V. 
— 
. — 
— 
0 
— 
— 
36 
17 
84 
13. V. 
— 
— 
— 
0 
— 
— 
49 
18 
90 
19. V. 
— 
.— 
— 
0 
— • 
— 
38 
19 
91 
20. V. 
— 
— 
— 
0 
— 
— 
16 
+ .S denotes that an undetermined number of eggs were laid which subsequently 
shrivelled up. 
