74 
Biology of Ixodidae 
10,000 eggs. By counting the number of eggs along two sides of the 
square and multiplying the figures we obtain with a considerable 
degree of accuracy the number of eggs which covers the area\ 
When enumerating by this method, we separate the eggs composing 
the mass by immersing them in normal salt solution and rubbing them 
about gently with the aid of a fine camel’s hair brush. When the eggs 
are fairly well separated they are transferred with some of the fluid into 
the frame of the apparatus and the slide ((7) is put in place. The eggs 
are now spread in a single uniform layer over the stippled area as 
shown in the figure, this being readily accomplished with the aid of a 
fine brush after draining away the superfluous fluid with a piece of 
filter paper. The eggs are readily ranged closely side by side like 
mai’bles. The counting can be done under a low power. 
IXODES PUTUS. 
The ticks (N. 1307)^ upon which the following observations were 
made were collected by me in large numbers on 2. vii. 1911 about the 
nests of guillemots at Worm’s Head, Gower, Glamorganshire, South 
Wales. The nests were situated in caverns and hollows in the rock upon 
precipitous cliffs, and access thereto could only be gained by descending 
from the brow of a cliff by means of a rope. A single bird’s egg usually lay 
upon the damp mud which covered the rock. The ticks were found in all 
stages excepting that of unfed larvae. The engorged larva was described 
and figured by me in an earlier paper {Parasitology, v. p. 60). Whilst 
collecting specimens among the rocks a great number of unfed females of 
I. putus were captured upon the exposed rocks and the clothing of myself 
and my companion. No other stages were found wandering about. Only 
about a dozen adult males were captured and all of these were found 
either in copula or in close proximity to gorged females which were 
hidden in small hollows in the mud beneath loose stones; twice I found 
a couple of males together, the one in copula, the other waiting along¬ 
side the female. A single dead and shrivelled female was found beside 
a mass of eggs, likewise lying hidden in a muddy cavity beneath stones 
and aggregations of gorged larvae; unfed nymphs and replete nymphs 
1 Eggs do not suffer from the manipulation incidental to counting, the larvae hatch 
out within the usual period and are normal. 
2 On 4. VII. 1912 a second lot (N. 1703) was collected for me in the same place. 
The description of the adults and nymphs will be found in Ticks, Part II. pp. 256-261 ; 
it is accompanied by figures. The little hitherto known of the biology of this species is 
described on p. 317. 
