390 
PKOCEEDINGS OF THE SOCIETY. 
Meeting of 17th April, 1895, at 20 Hanover Square, W. 
The President (A. D. Michael, Esq., F.L.S.) in the Chair. 
The Minutes of the Meeting of 20th March last were read and 
confirmed, and were signed by the President. 
The List of Donations (exclusive of exchanges and reprints) received 
since the last meeting was submitted, and the thanks of the Society were 
given to the donors. 
From. 
10 Slides (consisting of 2 of Seeds of Orchid, Septum of Club-rush, 
Wing of Hakea-seed, Auliscus cxlatus, Spicules of Gorgonia 
and Melitxa, Sertularia elongata , Sert. unguiculata , and 
Gizzard of Green Grasshopper) Mr. W. M. Bale. 
R. Braitkwaite, British Moss Flora, pt. xvi. (4to, London, 1895) The Author. 
Prof. F. Jeffrey Bell said that their list of donations included the 
valuable gift of a lantern with Microscope attachment, presented by 
the South London Microscopical and Natural History Club, which would 
no doubt prove extremely useful to the Society — also Part 16 — com- 
pleting the second volume of Dr. Braithwaite’s British Moss Flora — and 
some slides from Mr. Bale, sent from Australia, but at present without 
any communication with reference to them. 
The President said they had already at the previous Council Meeting 
expressed their thanks to the South London Society for their valuable 
and useful donation, and the meeting would no doubt also desire to vote 
the thanks of the Society to Dr. Braithwaite and Mr. Bale. 
Prof. Bell said they had received a special communication from the 
Imperial Institute relative to an exhibition of examples of photographic 
art which it was proposed to hold in that building. One section was 
to be devoted to photomicrography and apparatus connected therewith, 
and Sir Frederick Abel asked the Secretary of the Society to draw the 
attention of the Fellows to the matter as set forth in this communication. 
It would therefore be laid upon the table in the Society’s Library for the 
perusal of any one who felt interested in the subject. 
Mr. A. Letherby read a short paper upon the structure of the Podura 
scale, and exhibited a photograph in illustration of his opinion that the 
scale consisted of an upper and under layer, and that the so-called 
exclamation markings were perforations in the upper membrane. 
Mr. E. M. Nelson said he had seen this photograph and noticed 
the remarkable sharpness of the image and the clearness with which it 
showed the postage-stamp fracture. All were aware that there w r ere 
differences of opinion as to what the markings really consisted of, some 
regarding them as elevations and others as depressions ; but, so far as 
he knew, this perforation theory was new. 
