368 



KNOWLEDGE. 



September, 1910. 



FLOODS IX J. \1'.-\N.— Telegraphic coimnunic.itions 

 report disastrous floods in Japan. In Toldo alone thirty 

 thousand houses are said to be submerged, over eleven 

 hundred persons are reported drowned or missing, and two 

 hundred thousand persons are said to be in receipt of public 

 relief in consequence. 



METEOROLOGICAL OFFICE.— Announcement is made 

 that the Meteorological Office is to be removed in the coming 

 autunui to new premises at South Kensington. The Office is 

 at present housed at No. 63. Victoria Street, Westminster, in a 

 building designed for residential flats. The accommodation 

 available there has long been felt to be inadequate, and a 

 new building has now been erected by H.M. Office of 

 Works in the E.xhibition Road, which will accommodate 

 the Meteorological Office in its upper part, while the base- 

 ment and ground floor will be utilized for a Branch 

 Post Office. In connection with this removal some new 

 appointments have been made. Mr. R. G. K. Lempfert, M.A., 

 at present Superintendent of Statistics, becomes the Super- 

 intendent of the Forecast Division, and will be succeeded in 

 the Statistical Department by Mr. E. Gold, M.A., Scliuster 

 Reader in Dynamical Meteorology in the University of 

 Cambridge. Mr. R. Corlen, M.A., has been re-appointed .as 

 Special Assistant to the Director, with additional duties as 

 Secretary and Clerl< of Publications. 



MICRO.SCOPY. 



By A. W. Sheppakd, F.R.M.S., 

 witli the assistance of the following niicroscopists : — 



Alii Ml K ' '. Hani-ielu. Artiil-r Earlanm, 



Iamks iURroN. Richard T. Lewis, F.R.M.S. 



The Rev. E. \V. BciWELl, M.A. Chas. F. Roisselet, F.R.M.S. 



Charles H. Cf.n'y;<. D. J. .Scolkfiei.I), F Z.S., F.R.M S. 



C. n. Soar, K.R.M.S 



ON MOUNTING IX HARDENED GLYCERINE 

 JELLY. — Mr. William N. Allen, of the Dublin Microscopical 

 Club, has brought under our notice a method of mounting in 

 glycerine jelly which may prove of some interest to our 

 readers. It is specially applicable to small delicate plants 

 such as Hepaticae, Jungermannieae, and so on, where it is neces- 

 sary to preserve the specimen entire for purposes of future 

 examination. The method consists in hardening the glycerine 

 jelly by the use of potassium bichromate. The selected 

 specimen is mounted in the glycerine jelly in the usual way, 

 allowing sufficient jelly to surround the cover-glass to the 

 extent of about one-eighth of an inch. When set a ten per 

 cent, solution of potassium bichromate is painted over the 

 jelly and allowed to soak in for about ten to fifteen minutes, 

 the superfluous solution is then removed by means of filter 

 paper, and the slide put away in a dark place until the 

 solution has permeated the jelly, which will be complete in 

 about twelve hours. The slide is now exposed to daylight 

 until the yellow colour has disappeared. After a week or so 

 the excess of jelly may be removed ; the slide does not 

 reqviire either cementing or ringing. The specimen of 

 Plagiochila asplenioides mounted by this method some nine 

 months ago, is excellent, and still retains its delicate colour. 

 How far this method can be extended to the preservation of 

 the green freshwater algae, is a subject for experiment which 

 some of our readers may wish to try ; most workers in that 

 subject having found the usual methods of preserving green 

 algae to be niort or less vnisatisfactory. 



LEAF-SCALES IN THE GENUS ELAEAGNUS.— 

 The majority of amateur niicroscopists are quite familiar with 

 the scarious, discoidal leaf-scales found on the under surface 

 of the leaves of Hippopliae rhaninoides or Sea-buckthorn 

 the solitary British representative of the order Elaeagnaccae. 

 These scales are exhibited in a umch more perfect manner on 

 the under surface of the lca\ es of plants belonging to the 

 allied genus Elaeagnits, the best known species of which is 

 the Oleaster, or Wild Olive of our shrubberies. In the case 

 of Elaeagnns pnngens,the Natsu-Gumi, of China and Japan, 

 the harsh rigid leaves are thickly covered on the under surface 

 with brownish scales, producing a feeling of roughness when 

 the leaves are drawn between the fingers. The scales have 



the fringed margin turned slightly upwards, presenting a 

 concave surface to the observer. In other species, such as 

 E. unibellata, the Masiro-Gumi, of Japan, the under surface 

 of the leaf is of a silvery metallic appearance. The latter 

 is very characteristic of the Silver Berry, E. argenta. 

 In these species the fringed margins of the scales are 

 closely adpressed to the surface of the leaf, the siKery 

 appearance being due to the enclosed air. These very 

 characteristic leaf-scales are almost entirely absent from the 

 leaves of E. oricntalis, where the surface is closely covered 

 with many-rayed stellate hairs, the few scales present being 

 restricted to the mid-rib of the leaf. 



THE CULTURE OF FLAGELLATES ON SOLID 

 MEDIA. — The June number of the Quarterly Journal of 

 Microscopical Science (vol. Iv, part ii) contains a paper by 

 Mr. C. M. Wenyon, Protozoologist to the London School of 

 Tropical Medicine, on " Some observations on a Flagellate of 

 the genus Cerconionas." In this paper the author gives details 

 of the culture of such organisms as Flagellates on solid 

 agar media. This may be carried out in an ordinary Petri 

 dish, where the progress of the culture may be watched under 

 a low power of the microscope. A very useful method for 

 this purpose, and one which will allow of observation being 

 made with high powers, is the following: — A long cover-glass 

 (one and a half inches) is taken and carefully cleaned. On a 

 clean slide ridges of Czokor's wax are so arranged about an 

 eighth of an inch high that the cover-glass will form the lid of a 

 box. Some of the medium is melted by placing the test tube 

 containing it in boiling water, and a drop of this is allowed to 

 fall on the previously warmed cover-glass, and, by carefully 

 tilting it, the fluid medium is made to form a thin film ; this is 

 now allowed to solidify. The surface of the medium is 

 inoculated with a small quantity of material from a previous 

 culture, and the cover-glass carefully inverted on the wax 

 ridges. By means of a hot wire and more wax the whole is 

 now completely sealed up. It is most essential that this is 

 thoroughly done, as, if an opening be left, it will be found that 

 the medium will quickly dry and the culture cease. In this way 

 it is easy to follow the nuiltiplication of the Flagellates with a 

 one-six inch objective, and if the film of the medium has been 

 made sufficiently thin an oil immersion lens may be employed. 

 Berliner, who first used this method of culture for Flagellates, 

 found that they multiply rapidly, and in every case their chief 

 nourishment seems to be the numerous bacteria that grow on 

 the medium at the same time. 



THE MICROLOGIST.— We have received from Messrs. 

 Flatters, Milborne & McKechnie, Ltd., the first number of the 

 Micrologist, which will be published quarterly. The main 

 objects for which this Journal is established are to instruct 

 learners in microscopical manipulation, and in the methods of 

 preparing objects for examination, or, in other words, to teach 

 the methods of preserving the results of research. The 

 Journal will, in extent, cover practically all branches of 

 Biology, and will gradually work upwards from the simple to 

 the more complex methods, and will afterwards take special 

 types not generally dealt with in the ordinary text book. It 

 will be illustrated both with figures in the text and with actual 

 photo-micrographs. The present number deals very fully with 

 the methods to be employed in dry mounting, and is illustrated 

 with five photo-micrographs of objects mounted by that method, 

 that representing the dried seeds of Spergularia marina 

 being specially worthy of mention. 



THE EVOLUTION OF THE CrREFN ALGAE.— In 

 the current number of Science Progress, Dr. Fritsch com- 

 pletes his study of the Phylogeny and inter-relationships of 

 the Green Algae. It is the purpose of the article to indicate 

 briefly the diverse lines of evolution that can at present be 

 traced among the Green Algae, and to consider their connec- 

 tion with the Flagellates. Modern research has shown that 

 we must distinguish two clearly-marked classes amongst the 

 Green Algae — the Isokontae and the Hcterokontae, and these 

 are both linked by intermediate forms with the group 

 Flagellatae which shows a curious mixture of plant and 

 animal characteristics, and are probably the survivals of the 

 simplest group of organisms from which both kingdoms have 



