N. CUNLIFFE AND Gr. H. F. NlJTTALL 
339 
Dimensions of the egg. 
According to Nuttall and Warburton (1908), Dutton and Todd record the 
size of the egg as 0-9 x 0*8 mm. During the course of these experiments 
however, 193 eggs were measured immediately after deposition, being ovi¬ 
posited by four different females. The minimum, maximum and mean 
measurements of length x breadth were 0-9 x 0*8 mm., T5 x T1 mm. and 
1-06 x 0-92 mm. respectively. The maximum records approximate closely to 
figures obtained for the egg of 0. savignyi. The eggs (mean measurements 
T19 x TO mm.) of one female were distinctly larger than those of the other 
three, although their fertility was very low, only 11 per cent, producing 
larvae. The variation in size in the other batches was negligible even from 
different parents. The age of the female appears to have very little influence 
on the size of the eggs, very similar mean measurements being obtained from 
batches of eggs deposited after intervals of 70 and 140 days. 
When first oviposited the egg is light straw-coloured and translucent. It 
darkens in a few hours at 30° C. but much more slowly at 22° C., at which 
temperature it may take from 24 to 30 hours to attain the final dark brown 
colour. The normal coloration is lighter than in the case of 0. savignyi. 
Dimensions of unfed stages. 
As very little information is available 1 with regard to the sizes of the 
different stages, particularly of unfed individuals, and as a considerable amount 
of material, from one stock, had been bred under control, it was considered 
that the measurements detailed in Synopsis V would be of interest. These 
data were obtained by outlining, under the binocular microscope, the dorsal 
surfaces of unfed specimens, the breadth being taken as the distance between 
the spiracular depressions. 
Synopsis V. Dimensions of stages. 
Measurements in mm. to nearest tenth from unfed specimens preserved in 
70 % spirit shortly after emergence. 
No. of 
Min. 
Max. 
Mean 
individuals 
Stage 
Length x Breadth 
Length x Breadth 
Length x Breadth 
observed 
Larva 
0-8 x 0-7 
1-3 x M 
11 x 0*9 
80 
1st ® 
1-0 x 0*7 
1*3 x 1*0 
1*2 x 0*9 
74 
2nd ® 
1*2 x 1*0 
2*2 x 1*6 
1*6 x 1*3 
54 
3rd ® 
1*8 x 1*4 
3*4 x 2-4 
2*7 x 2*0 
23 
4th ® 
2*8 x 2*0 
4*5 x 3*1 
3*7 x 2*5 
26 
(J from 3rd ® 
3*8 x 2*4 
4*9 x 3*3 
4*6 x 3*0 
35 
5th ® 
3*1 x 2*2 
6*1 x 4*3 
4*6 x 3*2 
39 
<$ from 4th ® 
4*0 x 2*6 
6*3 x 4*3 
4*9 x 3*2 
137 
$ from 4th ® 
4*9 x 3*2 
8*1 x 5*4 
6*1 x 4*0 
69 
6th ® 
5*3 x 3*4 
— 
5*3 x 3*4 
1 
(J from 5th ® 
4*6 x 3*0 
6*0 x 4*4 
5*3 x 3*5 
19 
5 from 5th ® 
5*0 x 3*2 
8*9 x 5*9 
6*6 x 4*4 
78 
7th ® 
6*2 x 3*8 
6*9 x 4*3 
6*5 x 4*0 
2 
(slightly fed) 
6 ' 
$ from 6th ® 
6*7 x 4*3 
8*4 x 5-3 
7*4 x 4*7 
1 Vide Nuttall and Warburton (1908). It should be noted that prolonged starvation will 
accentuate the dorso-ventral flattening, therefore the measurements of a tick on emergence 
and after starvation may be different, the latter figures being the greater. 
