PROCEEDINGS OP THE SOCIETY. 847 



tlicy would find well worth looking at. In this animal the tube, instead 

 of being made with a simple bore, sometimes with a straight axis and 

 sometimes curved, was in the form of a screw, being twisted round upon 

 itself. Mr. Rousselet's drawing showed this very clearly. Mr. Western 

 also had a curious rotifer for exhibition. 



Mr. Western said it was a specimen of Botifer citrinus which was 

 found by Mr. Chapman on Wimbledon Common. 



The President mentioned that Pedalion was to be had in many places 

 in the neighbourhood of London about a month ago, where it had not 

 been previously found, though Mr. Shepherd had found it repeatedly in 

 the lily tank at Eaton Hall, near Chester. It was very curious to note 

 how, when a rotifer made its appearance in one locality it was generally 

 found in a number of other places surrounding, as if the eggs were 

 carried about and distributed by the wind along with the dust. He also 

 wished to draw a picture of what Mr. Rousselet had called his attention 

 to in connection with the small vibratile tags attached to the lateral 

 canals, the use of which had been so difficult to make out in the case of 

 Asplanchna. He had not mentioned it in the Supplement to the 

 ' liutifera,' but he found that in Daday's last memoir, printed in 

 Hungarian, it was shown quite plainly. Having made and exi^lained 

 drawings of the structure on the blackboard, the President said that the 

 conclusion he had come to was that the hairs were intended to protect 

 the oj)enings from the intrusion of any bodies which might tend to 

 obstruct the tubes, and if this was so it would seem to demonstrate that 

 there were openings. He had seen these hairs frequently loaded with 

 matter apparently strained out from the water. 



Mr. Ahrens's description was read of his new patent polarizing 

 binocular Microscope for obviating the difficulty of using analysing 

 prisms with the double tube. The inventor uses for an analyser a black 

 glass prism, set above the objective with a horizontal side upwards. 

 Two faces are symmetrically inclined to the optic axis at the polarizing 

 angle. The pencil is thus reflected at the proper angle, and at the same 

 time divided into two parts, which are then reflected up the two tubes 

 either by prisms or by plane reflectors (^ante, p. 685). 



The President said the Fellows must have heard with great re^^ret 

 of the deaths of the Rev. M. J. Berkeley and Dr. G. W. Eoyston-Picrott, 

 the former an Honorary, and the latter formerly an Ordinary Fellow of 

 the Society. They were both too well known to need any statement 

 from him as to their work. 



Mr. Crisp said they liad also heard of the death in America of 

 Mr. C. Fasoldt, sen., so well known as a ruler of fine lines. 



Prof. Abbe's paper, " Notes on the Effect of Illumination by means 

 of Wide-angied Cones of Light," was read {supra, p. 721). 



The President thought it would be obvious that a paper like that of 



Prof. Abbe's could hardly be followed when read to the meeting 



although full justice had been done to it in that respect by Mr. Crisp. 

 It could only be fairly dealt with when seen in print in connection with 

 the figures which illustrated it. 



Mr. T. F. Smith said that personally he had never objected to the 



