482 Bibliographical Notice. 



vulvae, takes a long time. At the conclusion of his paper Dr. Kroyer 

 describes three dubious animals belonging to the class of Entomo- 

 straca, of which particularly one, named Pegesimallus spiralis, is so 

 different from any known genus, in some respects reminding one of 

 the Annelide type, as fairly to puzzle the most ingenious divination. 

 The habits of the common Earwig, principally known from the 

 work of De Geer, have been made the subject of renewed investiga- 

 tion by Dr. Meinert. According to his observations, the eggs (30-70) 

 are laid in the autumn, as early as the beginning of October, though 

 in some cases only in the following spring. They are placed all in 

 a heap under bark or stones, in holes often dug by the mother, who 

 places herself over and defends them in danger. Dr. Meinert found 

 that when he dispersed the heap the mother collected it again ; and 

 once he saw an earwig covering with her body a hole filled with quite 

 young larvae, and keeping at bay for a considerable time a party of 

 yellow ants which had got access to her hiding-place on the removal 

 of the protecting stone. Although earwigs do occasionally use their 

 forceps for pinching, and with no mean force, this did not constitute 

 her mode of defence ; but whenever the ants in crawling about came 

 near the extremity of the forceps, she hurled them away by a quick 

 movement of that organ. At last she was obliged to leave her brood 

 in the power of the ants. Another time Dr. Meinert had three female 

 earwigs, each with a young family, in captivity under the same shade : 

 two of the mothers having been removed, their young sought and re- 

 ceived protection from the third and remaining ; but when she also 

 had been removed, they all separated and made good their escape. 

 The larvae appear in the spring, and have generally six-jointed an- 

 tennae ; some however have eight joints in their antennae, even before 

 leaving the egg, in which case Dr. Meinert supposes that the first 

 change of skin has taken place in the egg, as the points of the tarsi 

 and palpi were found encased in a loose membrane. The skin is 

 changed several times, the third joint of the antennae each time 

 dividing itself into three new joints, so that the number of joints 

 is increased with two each time ; the pupa has twelve, the imago 

 fourteen joints. The cases in which the wings of the imago are 

 formed in the pupa are coalescent along the middle. Both larvae 

 and pupae possess a pair of large fcetid glands, of which the ducts 

 terminate at the root of the forceps, one on each side ; they are largest 

 in the pupa, but disappear in the imago, where they are replaced 

 by two pairs of smaller flat glands, of which the external orifices are 

 situated at the back of those small knobs or ridges observed by Leon 

 Dufour and Westwood on the second and third dorsal segments. The 

 only external distinction between the sexes in the pupa consists, 

 according to Dr. Meinert, in a light- coloured line along the middle 

 of the 7th and 8th ventral segments in the female ; and Fischer's 

 statement, that even in larvae and pupae the sex may be recognized by 

 the number of joints in the abdomen, is therefore erroneous. Dr. 

 Meinert asserts that this number is the same in both sexes, as nume- 

 rous dissections have proved to him. He has also observed the copu- 

 lation, which is performed in a curious manner. The male is not on 



