ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 503 



also more complex. He thinks that, from the anatomical side, we as 

 yet know very little about how or what an insect sees, and he thinks it 

 highly probable that its sight is very different from our own, and tliat 

 continuous picture-vision forms no part of it ; he thinks it possible that 

 the compound-eye may have two or three distinct kinds of perception. 

 At the same time he is of opinion that the ocular powers of insects are 

 very perfect in their way, although that way may be very different from 

 ours. 



Hermaphroditism in Gastropacha.* — Prof. P. Bertkau describes a 

 case of external hermaphroditism in Gastropacha quercus, where the 

 right antennsB and wings were those of a female, those on the opposite 

 side characteristically male. In other ways the external secondary 

 characters were mingled, but the thorax and posterior body were wliolly 

 female. The state of the internal organs was at the same time investi- 

 gated, obviously a point of much importance. The gonads were wholly 

 degenerate, but there were almost normal female ducts and auxiliary 

 structures. There was no hint of internal male organs. Bertkau 

 believes that an individual has rudiments of both kinds of secondary 

 sexual characters, that predominance of one sex in the organism 

 suppresses the secondary features of the other, while complete atrophy 

 of the essential organs is naturally enough associated with an external 

 average. The author notes the occurrence of 315 cases of " hermaphro- 

 ditism " among Arthropods : — 8 Crustaceans, 2 Arachnids, 305 Insects. 

 Of the latter, 244 Lepidoi^tera, 48 Hymenoptera, 9 Coleoptera, 

 2 Orthojjtera, and 2 Diptera are known. Among Arachnids, a specimen 

 of Disea dorsata was male as regards cephalothorax, limbs, and palps, but 

 female in the hinder part of its body. 



Myrmecopliilous Insects.t — Herr E. Wasmann continues his 

 interesting investigations on the life of myrmecophilous beetles and their 

 relations to the ants. He distinguishes (1) true guests which are cared 

 for and fed by the ants (Atemeles, LomecJiusa, Claviger) ; (2) forms 

 which are tolerated but are not treated with special friendliness, and 

 which feed on dead ants or rotting vegetable material (Binarda, Hseterius, 

 Formicoxenus, &c.) ; (3) ant-eating species, pursued as enemies, or only 

 tolerated as a matter of necessity {Mijrmedonia, Quedius brevis, &c.), to 

 which may be added parasites like Fhora. The three sets are not 

 rigidly separable. 



Atemeles and Lomechusa have taken on some of the habits of their 

 hosts, and are more adapted than other myrmecoi)hilous insects. The 

 best known species of Atemeles (A. paradoxus and A. marginaius~) are 

 found most frequently in the nests of Myrmica, more rarely in those of 

 Formica and others. On the contrary, A. pubicoUis seems to be more 

 frequent in Formica nests. The species of Atemeles are lively animals, 

 constantly moving their feelers, and experimenting with everything. If 

 one be attacked by a hostile ant, it first seeks to pacify its antagonist by 

 antennary caresses, but if this is unavailing it emits a strong odour 

 which appears to narcotize the ant. Wasmann describes how the ants 

 feed the Atemeles and are caressed and licked for their care, how one 



* Verb. Nat. Ver. Preuss. Tlheiulcl. (SB. Xiederrbeiu. Gesell.), xlv. (1888) 

 pp. 67-8. 



t Biol. Centralbl., ix. (1880) pp. 23-8; Deutbcbe Entora. Zeitschr., 1886, 

 pp. 49-66, 1887, pp. 108-22; Tijdbcbr. v. Eutom., xxxi. (1888) p. 84. 



