26o 



HA RD Wl CKE 'S S CIENCE- G O SSI P. 



MICROSCOPY, 



Query. — After staining sections in picro-carmine, 

 what is the best method of fixing the yellow stain 

 before clearing and mounting? — ^J. J. A. 



The Diatomace^ of the American Waters. — 

 I thought that the subjoined list might prove of some 

 little interest to students of the Uiatomacere, as it 

 proves conclusively the great variety and versatility of 

 form to be found along the American seaboard : — 

 The list consists of some 26S diffL-rent forms (ac- 

 cording to Dr. Engels of Virginia), and is compiled 

 from a gathering made in Mobile Bay. That I may 

 not weary the reader, I have simply given the various 

 families with their varieties, which are as follows : — 

 Amphora, 30 varieties ; Amphiprora, 4 ; Achnanthes, 

 3 ; Anaulus, 2 ; Amphitetras, i ; Auliscus, 2 ; 

 Actinoptychus, 3 : Actinocyclus, 3 ; Asteromphalus, 

 I ; Biddulphia, 7 ; Bacteriastrium, 2 ; Campylodiscus, 

 5 ; Cerataulus, 3 : Coscinodiscus, 14 ; Cocconeis, 3 ; 

 Cymatosira, i ; Dimmeregramma, 4 ; Enyonema, 

 5 ; Euonologramma, 2 ; Eupodiscus, 2 ; Epithemia, 

 I ; . Euonotia, 3 ; Fragillaria, 2 ; Grammatophora, 

 I ; Gomphonema, 2 ; Hyalodiscus, 2 ; Mastogloia, 

 4 ; Navicula, 76 ; Nitzschia, 14 ; Orthosira, 3 ; 

 Odontiscus, i ; Pseudo-auliscus, i ; Pleurodesmium, i ; 

 I'leurosigma, 3 ; Plagiogramma, 4 ; Rhaphoneis, 6 ; 

 Sceptroneis, l ; Synedra, 3 ; Striatella, i ; Scolio- 

 pleura, l ; Systephania, i ; Stauroneis, 6 ; Surirella, 

 7 ; Terpsinoe, i ; Triceratium, 8 ; Triphyllopelta, i. 

 —Alfred ]V. Griffin. 



The Norfolk DiATOMACEiE. — Mr. F. Kitton, 

 Hon. F.R.M.S., has issued the first series of the 

 Norfolk Diatomacere in a strong, neat, and elegant 

 case. The slides are all named, and accompanied 

 liy a catalogue. The mounting, ringing, and 

 general turn-out of the series are remarkable for 

 carefulness and good taste. This series ought to be 

 very successful, for to possess the actual objects 

 themselves named by so high an authority as Mr. 

 Kitton, is surely better than mere illustrations of them. 



A cHEAr Microscope Holder. — I hit upon a 

 microscope holder the other day, which I dare say 

 many would like to try. It costs about a penny, and 

 works as well as a guinea one with universal brass 

 liinge. It consists of a turned American clothes peg, 

 held between two upright strijis of wood, and these are 

 bound at the top with an elastic band, which is passed 

 three times round them. The bottom end of the 

 strip is held by one screw to a block of wood. The 

 clothes peg thus has every motion, up and down 

 between the strips of wood, round upon its own axis, 

 and sideways on a hinge. My boys find it very 

 useful. — IVilliain Linton Wilson. 



The Journal of Microscopy. — This excellent 

 serial, edited by Mr. Alfred Allen, will lie better 



known to our readers as " The Journal of the Postal 

 Microscopical Society." Part 12, vol. iii., has just been 

 published, containing, besides a good deal of various 

 notes appertaining to microscopy and natural history, 

 the following papers— " On the Peronosporse," by 

 George Norman ; " The Organisms in Yeast," by 

 Henry C. A. Vine ; '• On the collection and prepara- 

 tion of the Diatomaceae," by Alfred W. Griffin ; 

 " Senecio vulgaris," by R. H. Moore; " Half an 

 Hour at the Microscope with Mr. Tuffen West," &c. 

 The papers on Peronospora, Yeast, and Senecio are 

 illustrated by beautifully executed lithographed 

 plates. 



Microscopic Slide Centrerer. — We have just 

 seen a very compact little instrument, registered by 

 Mr. A. B. Chapman, of Ipswich, for mounting objects 

 accurately in the centre of the glass slips, and for 

 applying the thin cover glass concentrically with the 

 object. It has two revolving backgrounds to con- 

 trast with the colour of the object, one being black 

 with white circles, the other white with black circles, 

 and so arranged that, by simply turning a little knob, 

 either can be used or both removed as desired without 

 touching the slip, which can be finished entirely 

 (except the ringing) before it is taken off the instru- 

 ment. It is so simple that there is nothing to prevent 

 any manipulation required in mounting the object, 

 and we recommend it to our microscopic friends. 



ToLU AS A Mounting Medium.— Mr. C. Henry 

 Kain calls attention to tolu as a mounting m.c- 

 dium, as it has a higher index of refraction than 

 styrax. For mounting, it should be dissolved in 

 alcohol or chloroform, preferably the latter. The 

 colour is a disadvantage, Init this does not seriously 

 affect thin mounts like diatoms. 



The Observation of the Lower Organisms. — 

 " Science Record" says, M. Leo Ewera has success- 

 fully used a solution of India ink in studying the 

 physiology of lower organisms. The ink is rubbed 

 up in water and added to the fluid in which the 

 animals and plants are living. The carbon of which 

 it is composed is so fine that it readily stays in 

 suspension, while by the absence of all noxious 

 qualities it does not interfere with the life of the 

 organism. It will be found very useful by those 

 studying Protozoa and unicellular algae. 



Geology of Tenby. — Reply to M. L. C.'s 

 questions in July number : I, Tenby is a good centre 

 for a collector of fossils to stay at. The coal-measures 

 and mountain limestone in the immediate neighbour- 

 hood are fairly fossiliferous, and fossiliferous Cambrian 

 and Silurian rocks are within easy access. 2. There is 

 no book on the Geology of Tenby, but a sketch of 

 the geology of that district will be found in a new 

 edition of " A Guide to Tenby," published at Mason's 

 Library, Tenby. — T. R. 



