444 
Biologi! of Ixodidae 
The time required hy R. bursa for metamorphosis. 
Egg to Larva. 
0 . of Lot 
Eggs laid on 
Larvae 
emerged 
after 
Eggs maintained 
at average 
temp, of 
st gen. 
16. vn, 1911 
51 days 
ca. 20° C. 
2n(i gen. 
Progeny of 
S No. 
2 
15. V. 1912 
47 
24° C. 
3 
21 V. 
44 
J? 
4 
22. V. 
43 
5 
21. V. 
45 
6 
23. V. 
43 
9f 
8 
25. V. 
43 
99 
10 
24. V. 
44 
99 
11 
27. V. 
46 
99 
12 
26. V. 
45 
99 
14 
26. V. 
46 
99 
15 
29. V. 
61 
20-5° C. 
16 
27. V. 
58 
99 
17 
13. vm. 
72 
18-2 C. 
18 
11. vm. 
67 
99 
19 
11. \mi. 
75 
99 
20 
10. vm. 
76 
99 
21 
10. vm. 
73 
99 
22 
11. vm. 
75 
99 
23 
9 vm. 
72 
99 
24 
10. vm. 
69 
99 
25 
10. vm. 
74 
91 
26 
10. vm. 
71 
99 
28 
14. vm. 
74 
99 
29 
9. vm. 
68 
99 
The effect of temperature is clearly seen from this table for at 
24° C. 
eggs hatched after 43-47 days 
d 
0 
O 
„ 50-58-61 days 
18° C. 
„ ,, 67-76 days. 
Larva to Nymph. 
Metamorphosis, uj)on the host, takes place in 4 or 
more days. 
Nymph to Adult. 
No. of Lot 
Rost 
Date on which 
gorged nymphs Adults emerged 
dropped off host after 
Ticks main¬ 
tained at 
1st gen. 
Ram 
9-12. XI. 1911 ca. 103 days 
ca. 19° C 
2nd gen. 
Ram 
23-25. n. 1914 12-14 days 
30° C. 
