PEOCEEDINGS OF THE SOCIETY. 
167 
probably stood higher in the scale of organisms than some other 
objects which were generally considered to be higher. He thought 
that these investigations of Mr. Ballinger would tend to raise such 
objects to a much higher rank than that previously assigned to them. 
The President said they had two other papers before them ; one of 
these was from Mr. F. A. Bedwell, “ On the Framework of the Mastax 
of Melicerta ringens and Gonochilus” and the other was a translation by 
Mr. Kitton of a paper by M. 'Paul Petit, “ On some New Genera and 
Species of DiatomaceaB.” The latter paper was, of course, unsuitable 
for reading in extenso, and would be taken as read. The paper by 
Mr. Bedwell was of considerable interest, and went into the minute 
structure of the organ at some length ; but in his opinion, apart from 
the illustrations (which would be handed round), it would scarcely be 
possible to do full justice to the author or his subject in the time left 
at their disposal, and it would therefore now be taken as read, and 
would appear in the Journal together with the illustrations in 
September. He would also call attention to the extremely good slides 
of the mastax of Melicerta and Conochilus made by Lord S. G. Osborne, 
which had been sent up by Mr. Bedwell for examination by the 
meeting. 
Mr. J. W.* Stephenson (Treasurer) read a “Note on the effect 
produced on P. angulatum and other Tests by excluding the central 
dioptric beam of light,” which he explained was accomplished by 
placing a central stop at the back of the objective, so that the diffrac- 
tion spectra alone formed the image. 
Mr. Frank Crisp (Secretary) said that, in view of the four months’ 
vacation now commencing, he should like to call the attention of 
the Fellows to the experiments on diatoms immersed in' a solution of 
indigo or other coloured liquid, a note of which had appeared in the 
last number of the Journal (vol. i. p. 79), and the important conclu- 
sions that those experiments pointed to, particularly in regard to the 
motions of diatoms. The experiments were well worthy of being 
repeated and confirmed, and if any Fellow during the vacation would 
be kind enough to do so, he would, no doubt, be able to make a very 
interesting communication to the Society when they met again. 
The President suggested that Professor Stokes should take up the 
question of the limits of visibility, which in his hands would doubtless 
receive some important advancement towards a conclusion. He also 
mentioned that some specimens of drawings reproduced by the auto- 
graphic process (which was exhibited at their recent scientific evening, 
by Mr. Pumphrey, of Birmingham) had been sent to the Society for 
distribution. 
At the conclusion of the meeting Mr. Stephenson exhibited P. 
angulatum under the conditions described in his “ Note,” and with the 
new oil-immersion lens, using a deep astronomical piece by Dollond, 
sen. The diatom appeared of a brilliant blue on a perfectly black 
ground, and the definition left nothing to be desired. 
Mr. Mayall, jun., also demonstrated the aperture of Tolies’ 
^ immersion lens by Professor Abbe’s apertometer. He first ex- 
hibited the apertometer with Zeiss’s new oil-immersion lens, recording 
