1877.] Scientific News. 699 ~ 
prominent makers, importers, and sellers of microscopes, has extended 
the scope of the work to other items of interest to microscopists, and will 
include in the publication, to be issued annually, various tables and data, 
and a list of microscopical societies, their officers, etc., after the model of 
that originally published in the Naruratist. The price of this con- 
venient little work is 25 cents. Persons interested are requested to send 
subscriptions and data tø the above address. 
XCHANGES.— Rare chemicals for the polariscope, starches, etc., 
offered for well-mounted slides; anatomical preparations preferred. 
Exchange lists printed for microscopists by papyrograph. Address G. 
E. Bailey, Lincoln, Nebraska. 
Plumule scales of small cabbage butterfly (Pieris rape), mounted, for 
good slides. Address Edward Pennock, 805 Franklin Street, Philadel- 
Shell sand from Bermuda, containing very fine foraminifera, spicules, 
etc., either mounted or unmounted. Address C. C. Merriman, Roches- 
oor, N. Y. 
a 
SCIENTIFIC NEWS. 
— A special meeting of the California Academy of Sciences was held 
August 31st, for the purpose of extending a formal welcome to a trio of 
distinguished scientists then visiting the State, namely, Sir J. D. Hooker, 
. Prof. Asa Gray, and Prof. F. V. Hayden. After eloquent ad- 
pen of welcome by the president of the Academy, Professor David- 
son, and by Messrs. Henry Edwards and R. E. C. Stearns, Sir J. D. 
Hooker returned thanks for the cordial welcome given, and said he came 
here to learn, and not to teach, and his visit was immediately due to the 
experience of his old friend, Professor Gray —a friend of forty years’ 
standing — and to the invitation of his old correspondent, Professor Hay- 
den, whose guests they had been during the time they spent in Colorado 
and Utah. His acquaintance with the vegetation of America had here- 
tofore been.an extremely slight one. In association with his father’s 
pursuits, who was for many years occupied in publishing investigations — 
of the plants of the British possessions of North America, he was led to 
the investigation of the Arctic flora. In the investigation he was struck 
with the uhiformity of vegetation extending round the whole globe in the - 
North. There was very little difference between the vegetation of 
America and the Old World within the Arctic circle; but upon close ex- 
amination he found that even the American flora was divisible into two 
sections by very slight but still definite characters ; that in crossing over 
from Greenland to the American islands, so called, there was a distinct 
change in the vegetation, though very slight. The opportunity he had 
now had of crossing the continent of North America from east to west, 
had shown him that that distinction is carried out to a very much greater 
