434 SUMMARY OF CUERENT RESEARCHES RELATING TO 



No free Euglenm were found in the water in which the Turbellarian 

 hosts were living. 



Chemical Products of Euglenae.* — 0. Biitschli has investigated 

 the chemical composition and physical properties of the films formed by 

 encysted Euglena granulata. There are two layers in these films, one of 

 which stains deeply with hematoxylin, and yields a carbohydrate-like 

 compound free from nitrogen. The surface of the film has abundance 

 of crystalline carbonate of lime, which may be due to the powers of 

 assimilation of carbon dioxide possessed by the Eugleme. If this is so, 

 it shows that tlie encysted flagellata assimilate. The second part of the 

 paper treats of the structure and origin of the paramylum grains. These 

 are flattened, ellipsoid, biconvex, or hourglass-shaped, with one or two 

 central cavities, which are canal-shaped, not spheroid, as in starch-grains. 



Variation in Infusoria.t — L. L. Woodruff points out that during 

 the life-cycle of many Infusoria, considerable variation of size and 

 shape occurs, along with marked structural and functional changes. 

 Such changes are not abnormal, and ought to be taken into account in 

 the determination of species. 



New Dinoflagellates.l — C. A. Kofoid deals with a large collection of 

 Dinoflagellates made by the * Albatross ' in the eastern tropical Pacific. 

 Noteworthy is the considerable number of new species of Amphisolenia, 

 Heterodinium, Geratium, and Oxytoxum. A new genus, Acanthodinium, 

 throws some light on the relationships of the problematical organism, 

 Cladopyxis, linking it with little doubt near to the Ceratiidse in the 

 system. A unique new genus, Centrodinium, is represented by three 

 species, and MurrayeUa, related to Oxytoxum, is also new. The plates 

 of the obscure and puzzling genus, Protoceraimm, are defined for the 

 first time, and three species are added to the highly phosphorescent 

 genus, Pyrocystis. The discovery of a new representative of Ptycho- 

 discus, a genus not reported since its description by Stern in 1H88, is 

 recorded. In all, three new genera, eighty-four new species, and nine 

 new " forms " are described. 



Structure and Systematic Position of Polykrikos.§ — C. A. 

 Kofoid discusses this Infusorian described by Ouljanin (1868) as a 

 Turbellarian, by Biitschli (1873) as an Infusorian, by Bergh (1881) as 

 one of the Cilioflagellata, and so on. He comes to the conclusion that 

 Polykrikos is a colonial organism of two, four, or rarely eight zooids, 

 and belongs to the Dinoflagellate family Gymnodinidse, sub-family 

 Polydinina3. Its peculiar " nettling organs " mark it as worthy of 

 generic distinction. It is represented by a single species, Polykrikos 

 auriculan'a, in neritic plankton, on coasts of Europe and California. 



Trichodinopsis paradoxa.|l — R. Issel gives an account of the struc- 

 ture and habits of this very remarkable Infusorian, a parasite of the 



* Arch. f. Prot. Kunde, vii. (1906) pp. 197-228 (1 pi.). See also Zool. Centralbl., 

 xiv. (1907) pp. 261-3. t Science, xxv. u.s. (1907) pp. 734-5. 



I Bull. Mus. Comp. Zool. Harvard, 1. (1907) pp. 163-207 (17 pis. and a chart). 

 § Zool. Anzeig., xxxi. (1907) pp. 291-3 (1 fig.). 



II Ann. Mus. Nat. Genova. xlii. (1905-6) pp. 334-57 (2 pis., 8 figs.)". 



