328 



and kept in a warm room. The mass to be cut is hardened in any desired 

 manner, and fastened by needles in the requisite position for cutting in a 

 paper case the same size as the well of the microtome. The celloidin solu- 

 tion is poured in as free from bubbles as possible, and allowed to Bet slightly. 

 The paper case and its contents is then placed in a quantity of methylated 

 alcohol of 80°, not less, as otherwise the celloidin becomes tough, and not 

 more, or it will dissolve it. It is left in this until of the proper con- 

 sistence to cut, about as firm as boiled egg albumen. If possible the 

 sections should be cut under the surface of methylated spirit, Katsch'e 

 machine is made for, and is simply perfect for this purpose, but sections can 

 be cut very well if the whole surface of the microtome in use is kept 

 flooded with spirit. The sections can be stained by any of the ordinary 

 fluids, the celloidin takes a slight stain, but as it is perfectly amorphous it 

 does not in any way interfere, and can, of course, if the species of section 

 admit it, be dissolved away by the mixture of ether and alcohol. On the 

 whole it seemed about the best thing for the purpose that he had met with, 

 and members might judge of its fitness by the fact that it enabled one 

 to cut sections of the whole eye, every structure remaining in situ, a feat 

 he supposed impossible with any other material. Celloidin might be obtained 

 from Messrs. A. and M. Zimmerman, 21, Mincing Lane, E.C., price 2s. 3d. 

 per cake. 



The Rev. H. J. Fase thought that the lamp which was exhibited by Mr. 

 Stokes might be improved if the stand was made oval instead of round, and 

 if made of thin stamped brass it would be very much lighter, and perhaps 

 less expensive to make. 



Mr. Stokes said of course the lamp did not pretend to be perfect, but he 

 thought the objection to an oval shape was the difficulty of making the 

 joints fit tightly. With a round tube the sections could be turned round in 

 any position, and would always work smoothly, but an oval one could only 

 slide up and down in one position, and would very soon get worn smooth 

 and loose. 



Mr. T. Curties exhibited a set of apparatus for collecting micros- 

 copic materiel, devised by Mr. Aylward of Manchester, consisting of a 

 japanned tin case containing three large sized glass tubes, part of the case 

 forming a strainer for draining off superfluous water ; another case, con- 

 taining six large tubes ; a third case, containing three bottles ; and a fourth 

 with four long tubes of smaller diameter. In addition to these there was a 

 clip for holding the tubes, and securing them to the end of any walking 

 stick by an ingeniously contrived tapering spiral wire; whilst a cutting 

 hook for detaching and obtaining portions of pond weeds was designed to 

 be fitted in a similar manner. 



The thanks of the moeting were voted to Mr. Karop, Mr. Stokes, and Mr. 

 Curties for their communications. 



Mr. E. M. Nelson called attention to some observations which he had 

 made on Spermatozoa, and pointed out, by means of drawings on the black 

 board, that the doubts which had been expressed as to the form of the 

 filament of the spermatozoon of the Newt, had been set at rest by the dis- 



