Volume XII 
JANUARY, 1920 
No. 1 
ON COLORATION IN TICKS. II. 
By GEORGE H. F. NUTTALL, F.R.S. 
(From the Quick Laboratory, University of Cambridge.) 
(With Plates I and II.) 
I. COLORATION IN LIVING TICKS. 
In a previous note on coloration in ticks (iv. 1913, Parasitology, vi. 49-51, 
PI. VII), reference was made to the appearances observed in living and dead 
specimens, the differences were indicated by coloured figures of Amblyomma 
variegatum (Fabricius) and A. splendidum Giebel, and the hope was expressed 
that future authors would, when practicable, describe the coloration as it is 
seen by daylight in living specimens. 
As a further contribution to the subject, I herewith offer two coloured 
plates reproducing water colour drawings from living ticks raised by me in 
Cambridge between 1912 and 1915, the plates having been prepared for in¬ 
corporation in our Monograph of the Ixodoidea. Camera lucida drawings were 
made by me as the groundwork for these figures all of which were lithographed 
by the late Mr Edwin Wilson. The latter painted the specimens under my 
direction, excepting one (PL I, fig. 4) which was drawn and coloured by me. 
Amblyomma hebraeum Koch. Plate I, figs. 1 and 2 represent living speci¬ 
mens (N. 1732, d and $) as they appeared 5. ii. 1914, i.e. two months after 
ecdysis and prior to feeding. The fasting ticks retain this appearance for 
months. PI. I, fig. 4 represents the scutum of a d of the same lot after it had 
remained anchored upon a ram’s scrotum for 77 days; it shows that a remark¬ 
able change in coloration may occur in ticks of this species that sojourn long 
upon the host. After 141 days upon the ram the colours in other specimens 
were found to have become even more intensified, especially the red areas at 
the sides. I referred but incidentally to this colour change in a previous paper 
(Parasitology ,x i. 395, d5). For an account of the biology of this species, the 
carrier of Heartwater in Africa, see Ibid. vii. 409-419. 
Amblyomma gemma Donitz. Plate I, figs. 5 and 3 represent the scutums 
of (N. 3016) living unfed d and ? specimens as seen on 4. ix. 1914, about two 
weeks after ecdysis, the specimens having been received from blast Africa. 
If we compare the scutums of these two species when alive, or when dead 
for weeks or years and dried or preserved in 70 per cent, alcohol, we may note 
the following differences (omitting finer details): 
Parasitology xn 
1 
