6 Proceedings of the Royal Physical Society. 
the larvee, which were then fed. By 6th May 1914 these burrows had been 
all permanently closed for pupation of the now full-fed larve, and remained 
closed throughout the following summer, autumn and winter. 25th April 
1915 was brilliantly sunny, and two beetles were observed in the act of 
emergence. One had been partially uncovered on the previous day by a 
shower of water, but in the case of the other the whole process was watched. 
First the tips of the mandibles were seen working through the earthen plug, 
and gradually a hole was made through which the head emerged. After 
looking about for a time the beetle withdrew again, and so remained for 
about an hour when it came finally forth. By 30th April 1915 all six of’ 
these burrows had been opened up by the emerging adults, and I had a 
total of eleven beetles running actively about in the breeding-cage. Five of 
these were males and six females. | 
SEX DISTINCTIONS. 
The males of C. campestris are somewhat smaller than the females, and 
may further be distinguished by the first three tarsal joints of the front legs 
being somewhat flattened laterally, and clothed on the under surface with 
bristle-like hairs. The females, besides being larger, may be recognised by 
bearing on the elytra, in addition to the pale yellow spots possessed also by 
the male, a pair of black dots, one on each elytron, near the scutellum. 
PAIRING. 
Not till the end of May was any inclination towards pairing exhibited, 
though the beetles were very active on bright days, and ate with avidity what 
was given to them. On dull days they seldom appeared, and showed no 
desire for food. 
In the last week of May 1915 another visit to Argyllshire was made. 
Tiger-beetles were very numerous. Half a dozen were caught and put for 
observation in a small portable breeding-cage. In the sunshine they paired 
readily, they also ate voraciously. On dull days they remained almost inert. 
There was a remarkable scarcity of larvee in the district. One sandbank 
where they had chiefly abounded was searched from end to end and only a 
single specimen found. 
THe Eac-Layine Hasits. 
In the early days of June it was noticed that some of the captive 
females were ovi-positing. They, however, suffered a great deal of dis- 
turbance from the other females in the cage. These would deliberately 
annoy the egg-layer, by running up against her, nipping her in the face, 
pulling her legs or seizing her round the body. Two ovi-positing females 
