N. ClJNLIFFE AND Gr. H. F. NUTTALL 
Synopsis IV. Duration of stages in days. 
Ticks kept at 22° C. Ticks kept at 30° C. 
r 
_ 
r 
A 
> 
No. of 
No. of 
individuals 
individuals 
Stage 
Min. 
Max. 
Mean 
observed 
Min. 
Max. 
Mean 
observed 
Egg to larva 
11 
25 
16 
226 
8 
13 
10 
166 
Egg to 1st ® 
20 
38 
23 
221 
13 
19 
14 
112 
1st to 2nd ® 
9 
20 
12 
379 
5 
8 
6 
405 
2nd to 3rd ® 
9 
26 
14 
303 
5 
10 
8 
371 
3rd to 4th ) 
® 9 
22 
15 
215 
6 
11 
8 
274 
® or adult j 
c?12 
18 
15 
33 
7 
10 
8 
16 
4th to 5th 
® 8 
35 
23 
109 
7 
11 
9 
128 
c? 11 
35 
23 
73 
8 
16 
10 
93 
® or adult j 
$ 10 
35 
20 
62 
8 
11 
9 
35 
5th to 6th ) 
® or adult f 
® 13 
c? 15 
$ 14 
21 
25 
13 
17 
16 
1 
7 
32 
9 
9 
7 
13 
17 
16 
12 
12 
10 
7 
13 
77 
6th to 7 th ) 
® 
No records 
23 
— 
23 
2 
® or adult J 
? 
10 
23 
15 
5 
(b) Discussion of Data. 
The casualties 1 from one cause or another were very large, as only 36-3 
per cent, of a total number of 1233 eggs were reared to the adult stage. About 
40 per cent, reached maturity at 22° C. and 33 per cent, at 30° C. 
The ratio of the sexes was practically equal, there being 235 males to 
212 females among the total number of adults reared. 
The number of ecdyses undergone by an individual before reaching 
maturity varied as shown in the following table: 
Number of Percentage of Percentage of 
ecdyses 
males 
females 
4 
20-8 
nil 
5 
70-7 
45-7 
6 
8-5 
51-5 
7 
nil 
2-8 
As two seventh stage nymphs were obtained but failed to mature, it would 
appear that occasionally a female individual may undergo eight ecdyse^ 
Males appeared after four to six and females after five to seven ecdyses, but 
whereas the majority of the males appeared after the fifth, the females 
appeared in approximately equal numbers after the fifth and sixth ecdyses. 
Herms (1916) states that in the allied species, 0. coriaceus Koch, the 
number of moults varies from four to seven. He also found, in the case of 
this species, that metamorphosis occupied a period of at least 159 days 
(? temperature) which is very considerably longer than was required under 
the conditions of the foregoing experiments. In the latter at 30° C., only the 
two last changes, namely the fifth to sixth and sixth to seventh nymphs or 
1 An unrecorded number of individuals of low vitality were rejected because they either 
failed to moult or refused to feed. Many of these could, no doubt, have been reared to maturity 
by being fed repeatedly, and would have matured under natural conditions. 
