2/4 COLEOPTERA CHAP. 



dead skins ; in this curious envelope it turns round, and in a couple 

 of days, having thus reversed its position, becomes lethargic and 

 changes to the true pupa, and in about a month subsequent to 

 this appears as a perfect Insect, at about the same time of the 

 year as it would have done had only one year, instead of two, 

 been occupied by its metamorphosis. M. Fabre employs the 

 term, third larva, for the instar designated by Riley Scolytoid 

 larva, but this is clearly an inconvenient mode of naming the 

 instar. Sitaris humeralis is now very rare in Britain, but it 

 seems formerly to have been more common, and it is not 

 improbable that its triungulin may have been the " Pediculus 

 meliUae," that was believed by Kirby to be a sort of bee-louse. 

 Some species of the genus Mdoe are still common in Britain, and 

 the Insects maybe seen with heavy distended abdomen grazing on 

 herbage in the spring. The females are enormously prolific, a single 

 one producing, it is believed, about 10,000 eggs. Meloe is also 

 dependent on Antlwpliora, and its life-history seems 011 the whole 

 to be similar to that of Sitaris ; the eggs are, however, not 

 necessarily deposited in the neighbourhood of the bees' nests, 

 and the triungulins distribute themselves on all sorts of un- 

 suitable Insects, so that it is possible that not more than one in 

 a thousand succeeds in getting access to the Antliopliora nest. It 

 would be supposed that it would be a much better course for these 

 bee-frequenting triungulins to act like those of E^ncauta, and hunt 

 for the prey they are to live on ; but it must be remembered that 

 they cannot live on honey ; the one tiny egg is their object, and 

 this apparently can only be reached by the method indicated by 

 Fabre. The history of these Insects certainly forms a most 

 remarkably instructive chapter in the department of animal 

 instinct, and it is a matter for surprise that it should not yet 

 have attracted the attention of comparative psychologists. The 

 series of actions, to be performed once and once only in a 

 lifetime by an uniiistructed, inexperienced atom, is such that we 

 should a 2 ]r 'iori have denounced it as an impossible means of 

 existence, were it not shown that it is constantly successful. It 

 is no wonder that the female Jfeloe produces 5000 times more 

 eggs than are necessary to continue the species without diminu- 

 tion in the number of its individuals, for the first and most 

 important act in the complex series of this life - history is 

 accomplished by an extremely indiscriminating instinct; the 



