172 PROCEEDINGS OF THE SOCIETY. 



The appearance of the nucleus of tho cell would lead to the notion that 

 such cells might perhaps be swarm-spores ; careful observation would, 

 however, be necessary to establish this as a fact. As regarded classifica- 

 tion, he should not be surprised if it ultimately turned out that these 

 organisms had a nearer relation to the true Ileliozoa than to the more 

 lowly Amcebee. 



The President expressed the thanks of the meeting to Dr. Gulliver 

 for his paper, and also to Prof. Stewart for his remarks upon the subject. 

 He thought that if one of the tendencies of fifteen or twenty years ago had 

 been to conclude that there was no structure in low organisms of the 

 type of that before them, it was equally certain that the tendency of the 

 present day was to show that there was structure throughout. This was 

 not yet established ; but even yet, if it should appear that the endosarc 

 was without structure, it was still certain that the ectosarc was shown to 

 be full of structure. 



Mr. E. M. Nelson handed round for inspection two photographic 

 positives, one of Amphipleura pellucida and the other of a kind of fungus 

 growth which attacked calcareous sand as described by Mr. J. G. Waller 

 in the ' Journal of the Quekett Microscopical Club ' (vol. i. p. 345). This 

 object presented some photographic difficulty because of its non-actinic 

 colour. With regard to the other, he might remark that, in resolving 

 diatoms with oblique light, it was essential to decide whether they in- 

 tended to focus upon the real surface or upon the optical image produced 

 in a higher plane, in consequence of the double nature of the structure 

 of the valve. In the latter case, they would obtain a result such as he 

 exhibited, which was a photograph of the optical image, and not of the 

 real diatom. He also exhibited the focusing screen for use in the micro- 

 camera which he described at the previous meeting of the Society. 



Mr. Nelson also called attention to a curious optical effect, for which 

 at present he was unable to account. In a flat box he had placed a 

 glass positive of Amphipleura pellucida, which was viewed as a trans- 

 parency through a piece of tube fitted at right angles to the surface. If 

 this was looked at when held towards a surface of light, such as an opal 

 lamp-shade or a " sun-light " gas-burner, the black lines appeared to be 

 slightly smaller than the white lines ; but if it was turned towards a 

 small light at a distance, then the black lines appeared very large, and 

 the white ones were reduced to mere threads. The scale of the photo- 

 graph showed that the effect was not due to the operation of the first 

 diffraction spectrum ; and it was still more curious to note that in the 

 case of another positive taken from the same negative, and upon the same 

 scale, this optical illusion was not observed. 



The following Instruments, Objects, &c., were exhibited :— 

 Mr. Crisp : — Edmonds's Mica Stage. 

 Dr. G. Gulliver : — Pelomyxa palustris. 



Mr. Nelson : — Photomicrographs. Diffraction effect of Amphipleura 

 pellucida. 



Prof. Stewart : — Thecalia concamerata. 



New Fellows : — The following were elected Ordinary Fellows : — 

 Messrs. H. Williams Case, Hahnemann Epps, Thomas W. Kirk, and F. 

 Raymond. 



