G . H. F. Nuttall 
75 
were found in similar situations. As the ticks were surrounded by mud 
constantly moistened by spray from the sea and scattered about by the 
birds returning from the water, I sought to maintain them, as far as 
possible, under natural conditions in the laboratory by placing the ticks 
in corked tubes containing the mud, or, better still, filter paper moistened 
with salt water, the tubes being kept in the dark or in a slightly 
darkened chamber. The salt prevented the growth of mould and it has 
since been found of use for the same reason in connection with the 
raising of other species of ticks. 
Observations on living specimens. 
The published descriptions of I. putus are based upon preserved 
specimens. It, therefore, appears desirable to record my observations 
upon the living tick without, however, repeating the detailed description 
of its external structures, regarding which the reader is referred to 
Ticks, Part 11. pp. 256-261. 
Fig. 2. Ixodes piitus, showing the arrangement of the intestinal caeca in unfed living 
ticks, the digestive organs being viewed through the transparent dorsal surface. 
Dotted lines indicate the contour of the scutum and cervical grooves in the first three 
stages and the cervical grooves in the male, (a) Larva 87 days, (b) nymph 6 days, 
(c) female, and (d) male 14 days after ecdysis. The ticks grow somewhat paler in 
general body colour after hungering for some time owing to the contraction of the 
caeca following upon their having become partially emptied. 
Male. During the first 24 hours after the young male issues from 
the nymphal skin its ventral surface appears slightly convex; viewed 
dorsally, the body appears dark owing to the material which occupies 
the still distended gut; pale areas between the folds of the gut are 
visible in positions corresponding to the cervical grooves and dorsal pits 
or grooves (Fig. 2 d). The legs and capitulum are a pale translucent 
yellow, the spiracles creamy. After 48 hours, owing to the intestine 
