PROCEEDINGS OF SOCIETIES. 919 
diatomaceous deposit more or less rich. The sea would in time 
wear away the narrow piece of land separating the mere from the 
ocean sand, and mud would be deposited over the entire area, and 
the mass of diatomaceous frustules, the accumulation of ages, would 
be consolidated into a white mass, such as we find in any ordinary 
deposit, the long rotting process having removed the brown endo- 
chrome. An instance was given of the gradual formation of such 
deposits before our eyes. Only the past summer the President had 
obtained a piece of tolerably white deposit from the bed of the 
Spring Ditch, which was in course of being filled up; it contained 
all the recent species which have been known to exist there by the 
previous examinations of microscopists. This once favorite locality 
is now destroyed through the extension of public works, 
In conclusion, the President hastily glanced over the various uses 
these deposits were turned to, instancing such commercial products 
as tripoli, plate powder, floating bricks for powder magazines on 
board ship, &c. 
The clays eaten by the natives of South America and in the in- 
terior of Africa were also, probably, diatomaceous deposits like the 
well-known Berg-Mehl of Lapland. 
Mr. H. Prescott pradncee a paper, entitled “The History and 
Physiology of a grain of Barley,” illustrating the germination of 
barley in its most rudimentary form, and then tracing its growth 
into a plant and the further development and structure of stem, 
root, flowering, spike, spikelets with floral appendages, sexual 
organs, pollen, starch, &c. 
The peculiarities of growth of stem (straw) structure and the 
various appearances of the inflorescence during different stages of 
deveiopment were illustrated by numerous etchings. 
On another occasion during the session, Mr. Prescott (‘On the 
Structure of certain Seeds’), failing time and opportunity to give 
the meeting the benefit of any special studies that he might be 
competent to undertake, which were still incomplete, thought that 
a work bearing immediately on the subject, prepared for the use of 
Government by Drs. Hooker, Carpenter, Graham, Lindley, &c. (a 
copy of which he was fortunate enough to possess), might have 
some interest for the meeting. Sketches and letterpress were both 
valuable, as showing how master minds commanded and carried 
through the working out of a subject quite new to themselves. In 
this instance, as in the determination of gennine and adulterated 
coffee, the meeting would not fail to observe how well the micro- 
scopic characters of the substances had been preserved in drawings 
which bore the stamp of truth upon them. The elaborate re- 
searches of Dr. Graham and others on the gravities of the different 
substances in solution were equally admirable. 
Mr. Hunter’s paper, ‘‘On the Structure of Animal Hairs,” was 
illustrated by numerons slides, including different coloured human 
hair, hairs from the several classes VS animals, insects, &e., and 
hairs from different parts of the body of the same species. Much 
emphasis was laid upon the difficulty of identifying individual hairs, 
