May 25, 18S3.] 



SCIENCE. 



467 



sliores of the Mediterranean, and two are cosmopoli- 

 tan. The dentition and anatomy form the subject of 

 two chapters, and are well illustrated. — (Mem. acad. 

 sc. Torino, ii. xxxv. ) w. H. D. [946 



MoUuscan fauna of Sardinia. — The land and 

 fresh-water shells collected by Caroti and others on 

 the island of Sardinia are treated of by the Marquise 

 Paulucci in a separately reprinted paper. The island 

 possesses thirty-one peculiar species, and one liundred 

 others, which are also found elsewhere. The work, 

 which is of a systematic and faunal character, is be- 

 lieved to be very complete, and extends to 247 pages 

 and 9 plates. — {Bull. soc. mal. Hal., 1883.) w. H. D. 



[947 



East-Indian Pulm onata . — God wi n- Austen, some 

 time since, published an article in explanation of a 

 plate prepared from drawings by the lamented Sto- 

 liczka, of rare and curious land-mollusks, which the 

 latter had observed in a living state during his ex- 

 plorations. In this way some valuable data were 

 made available for students. He has now contributed 

 another similar paper and plate in whicli species of 

 Oxytes, l-totula, Macrochlamys, Euplecta, and Rhys- 

 sota, are represented. In the same publication, 

 MoUendorf contributes several articles on Clausilia 

 of eastern Asia, the Nicobars and Japan. — (Journ. 

 Asiatic soc. Bengal, March, 1883.) w. H. D. [948 



Crustaceans. 



NeTv species and variability of fresh-water 

 Copepoda and Cladocera. — Under the deceptive 

 title of ' Heterogenetic development in Diaptomus,' 

 C. L. Herrick describes some varietal forms of spe- 

 cies of Diaptomus, describes a new species of Epis- 

 chura, and discusses the homologies of the limbs in 

 the genus ; remarks upon entozoic parasites of Ento- 

 mostraca, mentioning the occurrence of sucli para- 

 sites in Cydops and Daphnia; and describes new 

 species of Cyclops, Daphnia, Scapholeberis, Simo- 

 cephalus, and Ceriodaphnia, and some post-embryonal 

 stages of Daphnia. The paper is illustrated by three 

 plates. — {Amer. nat., April, May, 1883.) s. i. s. 



[949 



Crustacea in the Leyden museum. — Dr. J. G. 

 DeMan, in No. 3 of his Carcinological studies, gives 

 notes on a number of species of Portunidae and Ocy- 

 podoidea, most of them from the East Indies and the 

 west coast of Africa, and describes a new Geothel- 

 phusa from Java, and two new species of Sesarma 

 from the west coast of Africa. He adds Plagusia 

 depressa to the small but increasing number of spe- 

 cies of world-wide range, extending its habitat from 

 the West-Indian region to the west coast of Africa 

 and Amboina. — {Notes Leyden mus., v. 1-50. ) s. i. s. 



[950 

 Arachnids. 



Polymorphism and parthenogenesis of aca- 

 rids. — In an article on the gamasids, Berlese begins 

 with a resume of the anatomy of the group, and 

 then reports his observations on the development of 

 these animals. In this family nearly one hundred 

 species have been described, but many of them are 

 only polymorphic forms. An adult form may be 

 reached through two series of metamorphoses. One 

 is short, comprising only the larva, nymph and adult: 

 it may be called the 'normal' series. In the long 

 or ' abnormal ' series the number of forms is greater, 

 because a variable number of generations may inter- 

 vene. Thus, to give an example, Gamasus tardus 

 produces a larva whch changes into a nymph, and the 

 nymph into the adult tardus. Now, G. stercorarius 

 also produces similar young stages; but the adult 



stercorarius may change into a nymph, and that 

 nymph becomes a tardus. The nymphs cannot re- 

 produce. Moreover, stercorarius may be produced 

 either directly, or by metamorphosis of another ap- 

 parently adult form. The order of change cannot be 

 reversed. Except in the final form, parthenogenetic 

 reproduction seems to be common ; and perhaps the 

 impregnated eggs alone and always produce males. 

 No morphological character has been detected by 

 which the final forms may be distinguished from the 

 reproducing-nymphs. For this reason no new species 

 of this fainily can be described unlil the metamor- 

 phoses have been completely worked out. 



Berlese has worked out three species, — Gamasus 

 tardus, stabularis, and coleoptratorum. In each 

 there are three different nymphs, each of which has 

 its two sexual forms, besides which are the larva and 

 the two sexual adults, making twelve forms in all. 

 Finally there may be other intermediate varieties. 



Berlese has also observed a true paedogenesis, in 

 that the nymphs of Tachynotus inermis in one de- 

 velopmental series change directly into the adult, but, 

 in the second, produce an egg, although they have no 

 sexual orifice. — (Arch. ital. biol., ii. 108; Bull. soc. 

 ent. ita!., xiv. 88.) c. 8. M. [951 



Insects. 

 The Lucanidae of the United States. — Fuchs 



issues in a separate form, with a plate, his synopsis 

 of this group, which the Brooklyn entomological so- 

 ciety has been publishing by instalments in its bul- 

 letin. Enlarged figures are given of the antennae of 

 each of the fourteen species. [952 



The European Lixidi. — The biology, and par- 

 ticularly the food-plants, of the insects of this groui> 

 in its various stages, are given in a tabulated form 

 by Bargagli. Their food is shown to be largely com- 

 posed of thistles. — {Bull. soc. eat. ital., xiv. 312.) 



[953 



Thorax of Diptera and Hymenoptera. — 

 Brauer compares the thorax of Diptera and Hy- 

 menoptera, and concludes that no part of the first 

 abdominal ring ever enters into the formation of the. 

 thorax of the former. Latreille's ' segment mediaire ' 

 is to be met with only in Hymenoptera. Hammond's, 

 view, that the metanotum disappears in the imago of" 

 Diptera, is found untenable; and the thorax is com- 

 posed exactly as in Lepidoptera and Cicada. The 

 thoracic stigmata belong to the meso- and meta- 

 thoracic rings. Unfortunately the three accompany- 

 ing plates are very obscurely drawn. — {Sitzb. alcad. 

 wissensch. Wien, Ixxxv. ) e. b. [954 



Color - preferences of insects. — Bennett and 

 Christy have added a considerable number of careful 

 observations to those already recorded, on the habits 

 of insects when visiting flowers, which show, that, 

 as a general thing, butterflies do not confine them- 

 selves to a single species in many successive visits; 

 while flies are more constant, and bees, especially 

 Apis, are markedly so. Lepidoptera seem most fond 

 of red or pink, and of other colors in the following 

 order: yellow, blue, and white. The preferences of 

 Diptera are white, red or pink, yellow; and, of Hy- 

 menoptera, generally red or pink, blue, white, yel- 

 low. Bombus selects colors in the order, red, blue, 

 white, yellow. — (iVatore, March 29.) w. t. [955 



VERTEBRATES. 



Histogenesis of nerve-fibres. —His has studied 



this subject on human embryos. In one only, 2.1.5 



mm. long, it was found that the nucleated bodies of 



the cells of the medullary plate were already moi'e 



