36 
ment this term would vanish, and in the case of a circle 
would he the same at all points — thus agreeing with the 
two cases which have been worked out. 
MICROSCOPICAL AND NATURAL HISTORY SECTION. 
October 10th, 1881. 
Alfred Brothers, F.R.A.S., President of the Section, in 
the Chair. 
The President alluded to the death, in April, of Arthur 
George Latham, Esq., and a vote of condolence with Mrs. 
Latham was unanimously passed. 
Mr. Marcus M. Hartog, B.Sc., F.L.S., made some remarks 
upon damaged Indian rubber, and pointed out the ad visa- 
ability of treating it with a solution of magenta. This 
stains it most strongly where most damage has occurred. 
Mr. J. Boyd reported upon some parasites affecting the 
partridge, and the eggs were found amongst the feathers 
below the beak, just where the bird was unable to touch 
them. These eggs he afterwards exhibited under the micro- 
scope, and also a living specimen of the parasite, which was 
a species of Acarus. 
Mr. Boyd also mentioned the capture by him of the 6 of 
leptodora hyalina, near Keswick, distinguished by the great 
length of its antennse from the 9 at a glance. 
A discussion on the proportionate rarity of the 6 in the 
entomostraca and copepoda then ensued. 
