448 
PROCEEDINGS OF THE SOCIETY. 
was almost incredible, but some idea of it might be formed from experi- 
ments made by Prof. Leidy, who collected a number which had not been 
fed, and weighed them, and then on weighing them again after being 
fully fed he found that they were more than 100 times heavier than 
when unfed. 
Mr. E. M. Nelson made some remarks in further elucidation of his 
paper on “ Penetration in the Microscope,” showing that for his own 
sight the penetrating power was only l/7th of that given by Prof. Abbe, 
whose myopic sight accounted for the difference of estimate. Photo- 
graphs were shown in proof of the correctness of his contention, they 
having in themselves no focal depth. 
Mr. Nelson also gave a short resume of a note on the rings and 
brushes seen with the Polariscope — very beautiful effects, for the 
observation of which a petrological Microscope was generally thought to 
be necessary. This he showed was not essential, as wbat they wanted 
to see was not really a microscopic, but a telescopic object, so that all 
they had to do was to convert the Microscope into a telescope for the 
occasion, and this was readily done by placing an objective inside the 
tube of the instrument in the manner demonstrated. 
Prof. Bell said that, as mentioned at their meeting in March, the 
Council had been considering the possibility of making arrangements 
for a Conversazione on a somewhat more extended scale than had been 
attempted of late. As it was obvious that their usual place of meeting 
was too restricted for the purpose, the Council were of opinion that it 
might be as well — to borrow a legal phrase — to change the venue, and in 
doing this they thought it might also be well to change in some measure 
the character of the visitors. Definite arrangements could not, of course, 
be made at present, but it was proposed to hold the Conversazione in 
the autumn in some of the rooms at St. James’s Hall, and to issue 
cards of invitation to admit ladies also. The probable date would be 
November 30th, and, as ladies were coming, he was sure that Fellows of 
the Society would show themselves equal to the occasion by bringing 
for exhibition the most interesting objects they could find. 
The following Instruments, Objects, &c., were exhibited : — 
Mr. R. T. Lewis : — Living Larvae of Cattle Tick, recently hatched. 
Mouth Organs of same, multiplied by 400. 
Mr. E. M. Nelson: — Photographs, illustrating his paper. 
Mr. C. Rousselet : — Asplanchna priodonta , mounted. 
New Fellows : — The following were elected Ordinary Fellows ; — 
Messrs. Frederick Chapman, Frederick Richard Dixon-Nuttall, and 
Prof. J. W. Hoffman. 
