346 PROCEEDINGS OF THE 



so that at sunrise the pond scum was brilliant red again. The 

 President asked if any members had seen a similar appearance. 



Mr. C. F. Rousselet, when in South Africa with the British 

 Association in 1905, had noted near the Matoppo hills a similar 

 red Euglena, which he had not before seen. 



The Hon. Sec. paid considerable attention to the " Breaking of 

 the Meres," but had never seen red Euglena. He had observed 

 red scum, due to other causes. The phenomenon noticed by the 

 President was, however, not unique in this country. Some years 

 ago he had received some " red scum " material from Norfolk, 

 which was definitely identified as Euglena. The organisms were 

 crowded in their middle region with starch grains, and starch in 

 such a form that it was not affected by iodine. 



Mr. A. E. Hilton asked whether the red colour indicated the 

 decay of the chlorophyll formed during the previous day. 



The President did not think that the change from green to red 

 indicated any process of decay this change of colour was not 

 unique in Nature, as the snow plant could be obtained both red 

 and green, and apparently the change was due to nitrogen starva- 

 tion. He found this to be the probable cause when he had two 

 jars side by side, one red and the other green, and a fly had 

 fallen into one jar and had decayed ; the slightest trace of nitro- 

 genous food was sufficient to cause the change, which he thought 

 could not be regarded as a product of decomposition. Dr. 

 Cunningham thought that both kinds of pigment were present at 

 the same time, but that they were differently placed when the 

 change of colour was observed ; but whether this was the sole 

 reason for the change in the Euglenae was not certain. 



Mr. James Burton (Hon. Secretary) read a short paper, 

 " On the Disc-like Termination of the Flagellum in certain 

 Euglenae." 



Mr. James Burton also read a note on " A Method of Marking 

 a Given Object on a Mounted Slide." 



Mr. M. Blood said he usually put a spot of ink on the bright 

 spot of light formed on the slide by a high-power condenser, and 

 when it was dry, scraped the centre away. 



Mr. Spitta, after finding and centring the object in the field, 

 replaced the objective with a dummy of similar size, on to the lower 

 end of which had been fastened a rubber letter 0, such as is to be 

 obtained in small movable-type printing outfits. The letter is. 



