36 
the members had, for the first time, an opportnnity of seeing a human 
brain skilfuily dissected, and its manifold parts beautifully and simply 
explained. The nerves, blood-vessels, ventricles, etce., were all shown. 
while, at the same time, their various functions and their connection 
with the bodily organs weve made clear. The importance of carefully 
developing the brain, and maintaining it in health was strongly and 
eloquently urged. 
SIXTH SOIREE 
Fripay, 5tTa Marcu, 1880: Mr. W. D. LeSusrur, B.A., read 
a very interesting paper on “ Design in Nature,” in which, after dwel- 
ling on the spirit in which scientific investigations should be pursued, 
he proceeded to show the embarrassments in which scientific investiga- 
tors had involved themselves by a determination to find in nature a 
confirmation of preconceived theories. He quoted largely, in illustra- 
tion of this point, from the Bridgewater Essay of the Rev. Wm. Kirby, 
‘The History, Habits and Instincts of Animals,” and concluded by 
aie the view of nature taken by modern evolutionists. 
‘: On THE LAND AND FRESH-WATER SHELLS OF THE OrTawa,” Mr. Gitpzrt C. Heron. 
» * * * * * * * * 
There is very little variety in the land and fresh water-shells of this 
distri.t; and in this respect, it is very like the greater part of the Dominion of 
Canada. The reason for this want of number in species, as well as color, is the 
excessive heat and cold of our climate. While many of the shells are pleasing 
and the forms elegant, for the greater part they are but common, small in size, 
and want the fine coloring of those from the tropics. And those who have seen 
collections from uniformly warm countries, will, I fear, dispise the few specimens 
which occurred to me about Ottawa during the season ‘of last year. 
A shell found in all rivers and ponds : about Ottawa, and yet not common, is 
Shae decisa, Say. It will be tound on clay and sandy clay shores, burrowing 
in the mud near the water's edge ; alittle dome of clay will generally indicate 
where to dig for this gasteropod. I found associated with it, a little below 
Gatineau village on the Ottawa, a very interesting little Dymnaria-Pisidium 
adamsit (?) It has never been found in Canada before, or at least it is not on the 
lists, and is very rare. Valvata tricarinata, Say, is very common, yet it is the 
most extraordinary of our shells, and cannot be mistaken with its three keels 
and delicate green color. The three-keel variety only is found here, so far as I 
know, but the species may be seen semi-fossil in the marl beds with one, two, 
and three keels, butas often plain. Valvata humeralis, Say, is found in vast numbers 
in the little pond, in Dow’s swamp, near Billings’ Bridge, but has not been met 
with elsewhere so far. This shell may be the same as Valvata sincera, Say, but 
I have not seen a specimen of the latter, which is said to exist in the north-west 
