PROCEEDINGS OF THE SOCIETY. 395 



fungi, but they were very different from the flagellate cells of the 

 Bacteria, The presence of the flagella quite removed the Bacteria 

 from the mould fungi, with the oidia of which they were once com- 

 pared. It was a very puzzling thing that these flagella should only he 

 found in the case of young cultures. 



The thanks of the Society were unanimously voted to Mr. Dibdin 

 for his exhibit. 



Mr. A. E. Conrady gave a resume of his paper, " On the Application 

 of the Undulatory Theory to Optical Problems," diagrams in illustra- 

 tion of the subject being shown upon the screen. He said that as 

 the paper itself was largely mathematical, it was not quite suitable 

 for reading, but by the aid of the diagrams he was able to give a 

 general idea of its contents in a manner which would, perhaps, be 

 more clearly understood. 



Dr. Spitta said it was not given to everyone to understand a mathe- 

 matical formula, but when they had the subject reduced to a graphical 

 representation such as Mr. Conrady had shown them upon the screen, 

 what was otherwise too abstruse now became intelligible to most people. 

 He was curious to know if the method of explaining this subject had 

 originated in Mr. Conrady's fertile brain, as he did not remember to have 

 met with it in any of the text-books. 



Mr. Conrady said that this very interesting analogy was not originally 

 devised by himself, but would be found in the article on the Wave 

 Theory by Lord Rayleigh in the " Encyclopedia Britannica." It might 

 have found its way into some text-book, but he could not give a 

 reference to one. 



The President said he felt very strongly that papers of this kind, 

 dealing with Optics as bearing on Microscopy, were among the most 

 valuable of the contributions made to the Society. The present paper, 

 though put before them so clearly, was one which few Fellows would 

 feel able to discuss on the spur of the moment, but it would certainly 

 be read with great interest when it appeared in the Journal. 



The thanks of the Meeting were cordially voted to Mr. Conrady for 

 his communication. 



The Secretary read a letter from Mr. Alfred Mark Webb, Secretary 

 of the Selborne Society, inviting the assistance of Fellows of the R.M.S. 

 as exhibitors at the Selborne Society's soiree at the rooms of the Civil 

 Service Commission in Burlington Gardens on May 3rd. 



Also from the Secretary of the Manchester Microscopical Society, 

 calling attention to the publication of their Proceedings, and the terms 

 on which copies could be obtained. 



He also mentioned that some slides of Bacteria had been received 

 from Mr. C. J. Pound, of the Stock Institute, Brisbane, for distribution 

 to Fellows interested in the study ; these could be obtained on applica- 

 tion to the Assistant Secretary after the holidays. 



At the close of the Meeting the President made special reference to 



