I-.] APPENDIX, 47 



middle of the day. Coitus took place between another pair on 

 the 2.2x\6.^ and again on the 26th. 



I watched the gradual approach of death in many individuals : 

 some days before it ensued, the insects became sluggish, ceased 

 to fly and to eat, and only crept a little way off when disturbed : 

 they then fell to the ground and remained motionless, appa- 

 rently dead, but moved their legs when irritated, and some- 

 times automatically. Death came on gradually and impercep- 

 tibly ; from time to time there was a slow movement of the 

 legs, and at last, after some hours, all signs of life ceased. 



In one case only I found bacteria present in great numbers 

 in the blood and tissues ; in the other individuals which had 

 recently died, the only noticeable change was the unusual 

 dryness of the tissues. 



Carabus aitratus. An experiment with an individual, caught 

 on May 27th, gave the length of life at fourteen days ; this is 

 probably below the average, since the beetles are found, in 

 the wild state, from the end of May until the beginning of 

 July. 



Lucanus cervus. Captured individuals, kept in confinement, 

 and fed on a solution of sugar, never lived longer than fourteen 

 days, and as a rule not so long. The beetles appear in June 

 and July, and certainly cannot live much over a month. As 

 is the case with many beetles appearing during certain months, 

 the length of the individual life is shorter than the period over 

 which they are found. Accurate information, especially as to 

 any difference between the lengths of life in the sexes, is not 

 obtainable. 



Isolated accounts of remarkably long lives among beetles are 

 to be found scattered throughout the literature of the subject. 

 Dr. Hagen, of Cambridge, Mass., has been kind enough to 

 draw my attention to these, and to send me some observations 

 of his own. 



Cerambyx heros. One individual lived in confinement from 

 August until the following year ^ 



Saperda carcharias. An individual lived from the 5th of July 

 until the 24th of July of the next year^ 



' ' Entomolog. Mag.,' vol. i. p. 527, 1823. 



