PROCEEDINGS OF THE SOCIETY. 483 



poles. This and other slides which had been lent to him had shortly to 

 be returned to Prague, but he had brought them to the Meeting think- 

 ing the Fellows of the Society wonld like to see such interesting and 

 valuable preparations. 



The President said he had seen this specimen under a pocket lens 

 which showed the spindle quite distinctly. The extraordinary develop- 

 ment of the asters at the poles was very interesting. Among the largest 

 spindles to be found among plants were those in the pollen tubes of the 

 Cycads. 



The thanks of the Society were voted to Prof. Hartogforhis exhibit. 



Mr. Beck exhibited a portable Microscope, designed by Mr. Arthur 

 Hollick. The whole was packed in a mahogany box, the bottom of 

 which could be detached and then formed the base on which the Micro- 

 scope was fixed. The instrument was used chiefly for the examination 

 of botanical objects, but was equally useful for other purposes, and the 

 mirror was so mounted that it could be used as a reflector above the 

 stage in the proper position to converge the light upon the object- 

 swinging with the object as a centre. The socket which formed the 

 eye-piece holder when the parts were packed in the box, was utilised 

 as a lamp holder, when in use, enabling Microscope and lamp to be 

 handed round in a class without disturbing their relative positions. A 

 rotating cell made of cardboard formed a convenient revolving object 

 holder, and a simple method of mounting specimens in pill-boxes had 

 also been devised. Another point of some interest was the manner in 

 which the front of the objective had been coned off so as to reduce it to 

 the dimensions necessary to admit just as much light and not more than 

 could be utilised by the back lens. The objective exhibited was a £ in. 

 coned off in this way, and it was remarkable what an amount of illumi- 

 nation was obtained by this simple method. 



The thanks of the Society were voted to Mr. Beck for his exhibit 

 and explanation. 



Prof. J. D. Everett read his paper entitled ' A Direct Proof of Abbe's 

 Theorems on the Microscopic Resolution of Gratings,' which he illus- 

 trated by mathematical formula3 drawn upon the board and by the 

 exhibition of a slide as described in his paper. 



Mr. J. W. Gordon said : By the courtesy of Prof. Everett I have had 

 the opportunity not only of seeing the abstract of his paper which has 

 been circulated but also of reading the paper itself in advance. The 

 subject with which he deals is of particular interest to me because it 

 relates to an experiment first, as I suppose, suggested by myself, and 

 which formed, in a paper I had the honour of submitting to this Society 

 at the June Meeting in 1901, the basis of a criticism of the Abbe theory 

 as expounded by Naegeli and Schwendener. Perhaps, therefore, I may 

 be allowed to say, without presumption, that I have read the paper with 

 uncommon interest and that the proof which Prof. Everett gives of the 

 changing phase relation between different parts of the spectrum and the 

 effect of this changing relation in producing apparent movement in the 



