128 PROCEEDINGS OF SOCIETIES. 
it does not evaporate quite so readily. There is another 
point that I may notice in the paper that has just been 
read. The author mentions that by cutting off the heads 
of flies and grasping one of them between the finger and 
thumb the proboscis with all its apparatus will be pro- 
truded in the symmetrical arrangement proper for mounting. 
I invariably make use of this method. Take the proboscis of 
the blowfly for example. The flies are best when very young, 
having been hatched in’ a dark box, otherwise their probosces 
will be opaque and more intractable than when they have not 
been hardened by exposure to air and light. Having cut off 
the heads, they should be macerated for some hours in water, 
then on grasping the head between the finger and thumb, the 
proboscis will become highly inflated (indeed if the pressure 
is too great it will burst), then nip it between two slips of 
glass, having a small elastic band around them, to spring 
them together, now cut off the head, and leave the proboscis 
under pressure until it is dry; it will then retain its form, 
which will be quite symmetrical, and may be finally mounted - 
in Canada balsam in the usual way.” 
After some remarks from Mr. Brooke the discussion closed. 
The final Report of the Committee “ On the best uniform 
method of attaching Object-Glasses to Microscopes,” was 
read. Resolved that it be received and adopted. (‘'Trans,’ p. 
39.) 
December 9th, 1857. 
Grorcr SHapsott, Esq., President, in the chair, 
Captain John ‘Peel, 14, Ulster Place ; Geoffrey Bevington, 
Esq., Wandsworth Common; J. J. Harding, Esq., 1, Barns- 
bury Park; J. W. Harker, Esq., 24, Upper Barnsbury Street, 
were balloted for, and duly elected members of the Society. 
A short paper by Mr. B. J. Nowell was read, ‘ On the 
Menai Straits as a locality for the Collection of Diatomacez.”’ 
The author adverts to the fact that the mud of which some 
portion of the shore is composed is particularly rich in Dia- 
tomacere, and states that the gathering is best pursued be- 
tween high and low water mark, the surface and the bottoms 
of the little pools being skimmed in the usual manner. The 
united proceeds of these skimmings are to be placed in a 
shallow vessel and exposed to the sun for some time and then 
re-skimmed. It is then recommended that the usual manipu- 
lations with hydrochloric and nitric acids, assisted by heat, 
should be performed, the “ result being a collection replete 
- with beautiful forms.” Some slides containing the forms 
collected in this way having been transmitted by the author 
