20 



IIARDWICKE'S SCIENCE-GOSSIP. 



[Jan. 1, 1870. 



MICROSCOPY. 



Vulcanite Cells. — Your correspondent has 

 omitted to notice the Vulcanite Cells which are 

 now used by many microscopists in preference to 

 any other form of cell. They are fastened to the 

 slide by marine glue, and are perfectly free from 

 leakage. They can be obtained of any thickness from 

 Mr. S. A. Pumphrey, 21, Paradise-street, Birming- 

 ham, who sends 100 assorted to any address for 

 thirteen stamps. — R. H. Moore. 



Adaptation of Microscope.— Eor applying the 

 microscope to the examination of objects, contained 

 in aquaria, or too large to be placed upon the stage 

 of the instrument, I have lately adopted a simple 

 piece of apparatus, which was constructed for me 

 by Mr. Crouch, of London Wall, at my suggestion. 

 It merely consists of a metal plug, threaded to 

 screw into the horizontal arm in place of the body, 

 and supporting, at right angles to itself, a tube lined 

 with cloth just large enough for the body to slide 

 in. The coarse adjustment rackwork affords a 

 means of varying the height within certain limits, 

 and the body slides easily enough in the tube for 

 focussing. If the direction of the latter be reversed 

 (i.e., so that the eye-piece end projects over the 

 stage) the instrument may be inclined at any angle 

 over large objects laid on the table. Special forms 

 of microscopes for aquaria have been devised, and 

 any one who can afford to purchase them will 

 scarcely regret the outlay — and in many patterns 

 of students' and educational instruments the hori- 

 zontal bar has been superseded by improved 

 arrangements ; but there may be some persons to 

 whom this hint, how to increase the employment of 

 the microscopes they possess, at a trifling cost, may 

 not prove unacceptable. It is hardly necessary to 

 add that this contrivance answers best with the 

 lower powers. — William C. Atkinson. 



" Pseudogonidia."— Some days ago, while ex- 

 amining certain freshwater algae under the micro- 

 scope, I observed a rather curious phenomenon, 

 which I wish to record in the pages of this magazine. 

 I found among the filaments of the Vaucheria ir- 

 regular green granular masses, often (micro- 

 scopically speaking) of large size. The granules 

 of which they were composed exhibited active 

 motion, which may have been merely "molecular," 

 but which, was accompanied by the protrusion of 

 portions of the mass in a manner which I suppose 

 would be called "amoeboid." At first it struck 

 me that it might be amoeba itself, but a closer ex- 

 amination quite dispelled that idea. I soon con- 

 vinced myself that these bodies were portions of the 

 endochrome of the Vaucheria escaped from the cell. 

 It appeared that some of them (doubtless those 

 which had escaped longest) had secreted a mem- 



brane around themselves. This seemed to [put a 

 stop to the motion, though I once saw a flowing 

 movement of the granules after its appearance. 

 I several times saw similar round bodies (I think 

 without a membrane) still within the parent cell. 

 I feel no doubt that these bodies are the same as the 

 " pseudogonidia " described by Naegeli ("vegetable 

 cells," Royal Society, '45, '49), and others in 

 Bryopsis, etc. ; but I never remember to have seen 

 any motion in these mentioned. I think it worth 

 recording, as it is singular that the cell-contents 

 should be perfectly motionless in their natural 

 position, but begin to move immediately on be- 

 coming free. — Dukinfield H.Scott, Rooks Nest, God- 

 stone. 



Microscopical Manipulation. — We learn with 

 pleasure that Mr. W. T. Suffolk offers to repeat his 

 lectures on this subject to a class, from members of 

 the Quekett Microscopical Club, at the commence- 

 ment of the year. We hope that all who are 

 desirous of joining such a class will at once com- 

 municate with the Secretary of the Club, so that 

 Mr. Suffolk may have a full attendance when he 

 commences. 



Monthly Microscopical Journal. — This 

 journal has just completed its second volume of 

 three hundred and forty pages and contains a mass 

 of microscopical information ; lists of new books 

 published at home and abroad ; notes of the most 

 recent observations, improvements, and inventions ; 

 papers on the stirring topics of the day with which 

 the microscope is associated ; reports of the 

 meetings of microscopical societies, and altogether 

 forms a thorough digest of all microscopical matters 

 during the six months, and certainly at a most 

 reasonable price. Those of our readers who may 

 not already have tested its value should do so at 

 once. 



Cheap Eoreign Objectives. — It is alleged that 

 a young optician named Gundlach, of Berlin, has 

 succeeded in making object-glasses which are 

 cheaper and more powerful than those of Hartnack 

 and other opticians. His No. 7 is better than Hart- 

 nack's No. 9 or No. 10, at less than half the price 

 of the No. 9. It has higher magnifying power, 

 more light, and greater focal distance. Max Schultze 

 says that Gundlach's No. 8 is better than Hartnack's 

 No. 14, and is only a third of the price.— Monthly 

 Microscopical Journal. 



Plumules of Lepidoptera.— Mr. John Watson's 

 " further remarks on the plumules or battledore- 

 scales of some of the lepidoptera " appeared in the 

 Monthly Microscopical Journal for December, illus- 

 trated by three plates with figures of the plumules 

 of seventeen species. 



