46S 



described the " Spaiisa " Revolving Microscope Tray. He said 

 the microscope is placed on a cloth-lined tray which has two 

 extended arms connected by a circular block having on its under 

 side a centre-pin. This pin fits into an oak base. The under 

 side of the tray is fitted with " domes of silence," and can be 

 revolved on the centre-pin, the lamp being placed on the wooden 

 disc over the centre, and, revolving with the microscope, main- 

 tains its position constantly in relation to the instrument. The 

 device allows of several people using the same microscope in 

 succession with the minimum of inconvenience. 



Mr. C. Lees Curties, F.R.M.S., for Messrs. Baker, exhibited a 

 new three-lens dark-ground illuminator made to a formula by 

 Mr. Nelson, and an improvement on his former two-lens model. 

 It has a numerical aperture of 1'32, and works through a slip of 

 over one millimetre thickness. Being provided with the universal 

 thread, this illuminator can be used on almost any substage 

 fitting. 



A vote of thanks was passed to Messrs. Smith and Curties for 

 their interesting exhibits. 



Mr. James Burton read some notes on Freshwater Algae 

 collected in 1911. Mr. Burton's notes had special reference to 

 occurrences of the phenomenon known as the " breaking of the 

 meres." 



Mounted specimens of several of the species referred to were 

 exhibited under microscopes, and the paper was also illustrated 

 by coloured diagrammatic drawings. 



The thanks of the meeting were voted to Mr. Burton for his 

 paper. 



The Hon. Secretary read a note by Mr. E. M. Nelson, 

 F.E.M.S., descriptive of three high-power photomicrographic 

 lantern slides sent, and then projected on the screen. The first 

 was the eye-spot of Coscinodiscus aster omphalus, Maryland deposit, 

 styrax mount, showing fracture passing through cap, x 3,000. 

 Slide 2 was tubercle bacillus from sputum, showing the so-called 

 flagellum x 4*150. The preparation was made in the middle of 

 December 1911, by Dr. A. C. Coles, of Bournemouth, who gives 

 the following particulars : '* From sputum stained in ordinary 

 way by Ziehl Keelsen's method, and decolourised in 25 per cent, 

 sulphuric acid, counter-stained with aqueous solution of methy- 

 lene blue, mounted in parolein." A curved flagellum has been 



