548 SUMMARY OF CURRENT RESEARCHES RELATING TO 



contrasted with plants, and giving a short account of protoplasm and 

 the cell, the authors take a wide and interesting survey of the chief 

 classes of animals. The structural aspect predominates, but considerable 

 attention is paid to habits and life-history, and the particular feature of 

 the book is the great excellence of the half-tone illustrations, many of 

 which are from photographs of the real animals. 



Tunicata. 



Ovum within Testes of Fragarium elegans.* — W. Bedikorzew 

 found inside some of the vesicles which compose the male gonad of this 

 (of course, hermaphrodite) composite Ascidian, a large cell, — unmis- 

 takably an ovum. He recalls cases of an ovum within the testis of 

 unisexual animals, — lobster (G. Hermann), crayfish (von la Valette St. 

 George), and cockroach (Heymons). 



Heart of Molgula manhattensis.f — Gr. W. Hunter, jun., finds that 

 the heart proper of Molgula is made up of three different elements, so 

 far as the selective agency of methylen-blue shows : first, cross-striped 

 muscle-cells which do not take the stain ; second, connective tissue 

 elements which are closely applied to the heart musculature in a some- 

 what regular manner ; and third, nerve-cells and fibres. In the pre- 

 served material an extremely delicate pavement epithelium seems to 

 form the endothelial lining. 



Ascidians of Bermudas. J — W. G. Van Name gives a monographic 

 account of the Bermudian Ascidians, which have hitherto received but 

 little attention. Four new genera are described, and 21 new species, 

 out of a total of about 46. 



INVERTEBRATA. 



Fauna of a Mountain Stream. § — F. Zschokke gives an account of 

 the characteristic fauna of a rocky torrential stream near Sackingen. It 

 exhibits a marked resemblance to the fauna of high Alpine streams. 

 Very typical are the larvae and pupae of the Diptera — Liponeura 

 brevirostris, Simulia, and Chironomus, the young stages of Ephemerids 

 (Epeorus, Baetis, and Ecdyurus), certain Phryganidae, besides Perla 

 bipunctata Pictet and Nemura nitida Pictet. Among the submerged 

 moss there are minute Hydrachnids unable to swim, various forms of 

 Aturus, Feltria, Sperclionopsis, Hygrobates, and Atractides. The list 

 also includes Gammarus pult'X, Litnnsea truncatula, Ancylastrum jluviatile, 

 and the three stream Turbellarians — Planaria gonocephala, Polycelis 

 cornuta, and Planaria alpina, which succeed one another in that order 

 upstream, as Voigt has described elsewhere. 



Mollusca. 



Fauna of the Gulf of Triest.}] — E. Graeffe continues his admirable 

 faunistic account of the Gulf of Triest, the last published portion 



* Zool. Arizeig., xxv. (1902) pp. 484-6 (1 fig.), 

 t Anat. Anzeig., xxi. (1902) pp. 241-6 (3 figs.). 

 I Trans. Conn. Acad. Sci., xi. (1902) pp. 325-411 (19 pis.). 

 § MT. Bad. Zool. Ver., No. 11-2 (1902) pp. 27-41. See Zool. Centralbl.. ix. 

 1902) pp. 42-3. 



|| Arbeit. Zool. Inst. Univ. Wien, xiv. (1902) pp. 89-136. 



