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 auratus._ 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[14]. _Saperda carcharias._ An individual lived from the 5th of July until the 24th of July of the next year[15]. _Buprestis splendens._ A living individual was removed from a desk which had stood in a London counting-house for thirty years; from the condition of the wood it was evident that the larva had been in it before the desk was made[16]. _Blaps mortisaga._ One individual lived three months, and two others three years. _Blaps fatidica._ One individual which was left in a box and forgotten, was found alive when the box was opened six years afterwards. _Blaps obtusa._ One lived a year and a half in confinement. _Eleodes grandis_ and _E. dentipes_. Eight of these beetles from California were kept in confinement and without food for two years by Dr. Gissler, of Brooklyn; they were then sent to Dr. Hagen who kept them another year. _Goliathus cacicus._ One individual lived in a hot-house for five months. In addition to these cases, Dr. Hagen writes to me: ‘Among the beetles which live for more than a year,—_Blaps_, _Pasimachus_, (_Carabidae_)—and among ants, almost thirty per cent. are found with the cuticle worn out and cracked, and the powerful mandibles so greatly worn down that species were formerly founded upon this point. The mandibles are sometimes worn down to the hypodermis.’