548 SUMMARY OF CURRENT RESEARCHES RELATING TO 



We must caution the reader that it is not yet known whether the 

 frustiiles are perforated or not, as will be seen from an article soon to 

 be published in these columns. As for the presence of cilia within 

 the diatoms, we have no more reason to expect to find cilia there than 

 in any other cells in which the movement of protoplasm has been 

 observed — as in desmids, or in the cells of higher water-plants, for 

 example. Moreover, diatoms are not the only plants which move 

 without visible cause. The desmids, for instance, move with vigour, 

 and they are not inclosed in a silicious shell which obstructs examina- 

 tion of the interior. In young desmids especially the cyclosis can be 

 examined with satisfaction by high powers. Looking over the algas, 

 we find that the Oscillarice are quite as remarkable in their movements 

 as the diatoms, and we cannot yet explain it ; and in the animal 

 kingdom the Gregarinae also move without giving the least indication 

 of how the motion is produced. It is a subject for still further in- 

 vestigation, and we have no doubt that with good objectives, supple- 

 mented by staining fluids properly applied, the cause of the movement 

 will soon be discovered." 



Fossil Diatoms of Austria-Hungary.*— A. Grunow describes the 

 following fossil diatoms from Austria-Hungary : — (1) In the " Saug- 

 schiefer " of Dubravica, a large number of species. (2) The " Polier- 

 schiefer" of Tallya. The diatomic remains are here united together 

 with extraordinary firmness by silicic acid, forming variously radiating 

 microscopic masses of crystals, which renders the examination ex- 

 tremely difficult. (3) The argillaceous neogenous basalt-tufa of 

 Holaikluk. The most abundant form here is Melosira tenuis, also 

 closely united by silica, and often containing petrified silica in the 

 interior of the cells. (4) The diatom-stratum of Kis-ker, of unknown 

 age, with ordinary still existing fresh-water forms. (5) " Kieselguhre," 

 vivianite, and " ocker '' stratum of Eger and Franzensbad. Several new 

 forms. All the new species are depicted in phototypic illustrations. 



Diatom Types. — Dr. H. van Heurck is preparing a series of pre- 

 parations to illustrate his synopsis of Belgian diatoms, representing 

 the principal types and elucidating the critical species. There will 

 be about 350 slides, containing at least 400-500 forms, and 25 will 

 be issued monthly. M. Grunow will examine the slides to check 

 the determinations. 



MICEOSCOPY. 



a. Instruments, Accessories, &e. 



Bausch and Lomb Optical Co.'s New Binocular.f — The Bausch 

 and Lomb Optical Company have completed a binocular of their 

 " Investigator " pattern, which has some variations in the construction 

 and adaptation of the prism, and in the nose-piece in which the 

 prism is fixed. The notices which have so far appeared of its con- 



* Beitr. zur Palreont. Oesterr.-Ungarus u. d. Orients von Mojsisovics u. 

 Neumayr, ii. (1882). See Bot. Centralbl., xiv. (1883) p. 146. 



t ' The Microscope,' iii, (1883) p. 89, from tlie ' Odontographic Journal.' 



