10 Proceedings of the Royal Physical Society. 
a live maggot was placed in front of one of them, the movements of the larva 
seemed to incite the beetle to seize and devour it. Eventually one beetle 
after another ceased to appear. 
On 7th December, when the beetles had been hibernating for about two 
months, and after there had been a fortnight of frosty weather—the 
temperature on some nights sinking as low as 13° F. below freezing-point— 
two beetles, a male and a female, were taken from their retreats into a warm 
temperature. Both became quite active. One had been simply hibernating 
under a turf, and the other in a hole it had dug out for itself in the ground. 
Appearances, therefore, favour the expectation that the adult of C. campestris 
may live through a second winter.! 
The foregoing observations show that the life-cycle of a Tiger-beetle 
extends over several years. Whether these years be four or more depends 
chiefly on the amount of prey the larva is able to capture. 
Thus in my observations eggs that were laid between 12th and 20th June 
hatched out between 11th and 30th July. The resulting grubs, which were 
supplied with as much food as they could consume, had reached a length of 
half an inch when six weeks old. They then closed their burrows for 
moulting and re-appeared about ten days later. They continued to feed and 
make a little more growth till the second half of September when they closed 
for hibernation, the most mature closing first. When they re-open in April 
(1916) they may be slightly over half an inch long, and less than half the 
thickness of a mature larva; that is, they may be approximately one quarter 
of the full size. 
According to the foregoing notes larve first observed in their natural 
habitat in July 1912, when they were about half-grown, did not become egg- 
laying beetles till June 1915. My own grubs, from eggs laid in June 1915, 
will re-open in April 1916 measuring approximately one quarter the full size. 
These may possibly attain half size by July 1916, and from the foregoing data 
may be expected to reach full reproductive maturity in June 1919, giving a 
life-cycle from egg to egg of exactly four years. A typical life-cycle might 
therefore be made up as follows :— 
Ligg stage, about one month, say from mid-June to mid-July 1915. 
Larval stage, nearly three years, from mid-July 1915 till June 1918. 
Pupal stage, six or seven weeks, from early or mid-June till late July or 
early August 1918. 
1 Since the above was written an adult female has re-appeared above ground (April 1916) 
after hibernating during the winter 1915-16. It is now (May 1916) thirteen months since 
this adult emerged from the pupal chamber. 
