3*4 



SCIEXCE- GOSSIP. 



fixed in from six to twelve Lours, but the immersion 

 may be continued for twenty-four hours without 

 damage. The pieces are then transferred to 50 

 per cent, alcohol for one hour, and afterwards to 

 75 per cent, and 95 per cent, alcohol for half an 

 hour each. 



New j. r i~scn Immersion" Objective. — Messrs. 

 Watson & Sons hare sent us for inspection a new 

 ^ 3 -inch oil-immersion objective of then- ordinary or 

 ••Parachromatic" series. The aperture is only 

 moderate, i.e. 110 N.A.. but this is no disadvantage 

 for ordinary work, whilst it enables the cost of the 

 objective to be proportionately induced. The lens 

 submitted to us was an early one. but we can speak 

 highly of its performance. It was unusually fiat 

 in the field, its definition was excellent, and it bore 

 high eye-pieceing well. The corrections were for 

 the short tube-length. The cost of the objective 

 is only £4. 



New Maceration Medium for Vegetable 



Tissue.— Herr 0. Richter finds that strong am- 

 monia will macerate vegetable tissue without injury 

 to the cell contents, such as starch and aleurone 

 grains, chlorophyll granules, etc. The fluid was 

 used boiling, cold, and at a temperature of about 

 40° C. The rapidity of the maceration depends on 

 the temperature. 



[For further articles on Microscopic subjects see 

 pp. 294, 296, 303 and 305 in this number — 

 Ed. Microscopy. S.-G.] 



ANSWERS TO CORRESPONDENTS. 



W. D. N. (Kirkcaldy). — The condenser you 

 allude to at 17s. 6d. is an optical part only, and 

 would cost 32s. 6d. with mount complete. The 

 other condenser is, I think, complete, and being 

 made by the maker of your instrument would be 

 preferable. I believe I answered some queries on 

 this matter on a previous occasion. A camera 

 lncida is used at a distance of 10 inches from the 

 table, because that is the normal visual distance ; 

 but if the image is too large you can reduce this 

 distance, or preferably you can use a lower power 

 objective. It is not easy for me to advise you as 

 to a course of work, but I sympathise with your 

 desire to devote your time and your microscope to 

 more definite study. As you take an interest in 

 botany I think you could not do better for a 

 beginning than obtain a book on practical botany 

 and work steadily through it. say Stra-burger and 

 Hillhouse's " Practical Botany." published by Swan 

 Soimenschein at 10s. 6d. A new edition has 

 recently been issued, or you could pick up a cheap 

 second-hand copy in the booksellers' shops in 

 L-jthian Street and George IV. Bridge, Edinburgh, 

 for about half this amount. Try. for instance. 

 William Bryce, 54 Lothian Street. This book i> 

 eminently practical, and contains clear elementary 

 instructions on the use of the microscope and mount- 

 ing : so would serve admirably. If you were to work 

 through such a book, mounting your slides as you 

 went on, you would gain a knowledge of botany 

 and provide yourself with an occupation that would 

 never weary, but lead you on to further interests. It 

 is a mistake, too, to suppose that botany cannot be 

 pursued in winter. It is equally a mistake to idly 

 examine many diverse things, with no aim or 

 object in view. 



A*. T. (Chorley). — Of the specimens of pond life 

 which vou send me. No. 1 is a Turbellarian worm. 



a Planarian. The green forms to which you allude 

 are possibly Vortex viridis ; No. 2 is a young 

 leech ; No. 3 is a larva of one of the Nemocera, pro- 

 bably Ta/nypm maeulatus ; No. 4 is a polychaete 

 annelid in an immature stage. For Nos. 1. 2. and 

 4 the readiest book of reference would perhaps be 

 the " Cambridge Natural History," vol. ii., and for 

 No. 3 tLe same work, vol. vi., pp. 468-9, or Prof. 

 Miall's "Natural History of Aquatic Insects." 

 You could refer also for No. 1 to the " Encyclo- 

 paedia Britannica " article " Planarians." 



EXTRACT^ FROM POSTAL MICROSCOPICAL 

 SOCIETY'S NOTEBOOKS. 



[These extracts were commenced in the Septem- 

 ber number at page 119. Beyond necessary editorial 

 revision, they are printed as written by the various 

 members. - Ed. Microscopy, S.-G.] 



Notes by Johx T. Neeve. 



Marine Algae. — Odonthalia dentata (fig. 1). 

 with tetraspores : this species is found on the 



Fii.. 1. Odonthalia den 



ivith tetraspores. 



Scottish coasts, and does not occur south of 

 Berwick, except occasionally as a derelict cast 

 up on the shore. I have not found it myself, but 

 have received a few specimens from Arbroath. 



Rhoilomela subfusca witb tetraspores. 



where it grows in abundance. The frond, as its 

 name indicates, is tooth-branched and of a deep- 

 red colour, from four to twelve inches high. 

 Rliodemdo subfusca (fig. 2), with tetraspores : this 

 plant is abundant with us in the south, and is 

 often cast up on shore after a storm. The fronds 

 are filamentous, rather brown in colour, drying 

 to a black and uninteresting specimen : but the 



