euse University, will have charge of the work 
in embryology in the College of Medicine. 
Dr. EpwIin F. NorrHrup has resigned from 
the professorship of physics in the University 
of Texas. The students’ paper of the Uni- 
versity remarks: ‘‘ During the brief thirteen 
years that the University of Texas has been in 
operation there have been no less than five 
professors in this school. Their tenure of office 
has been short, and, in the main, their depar- . 
tures abrupt.’’ 
DISCUSSION AND CORRESPONDENCE. 
RESIGNATION OF THE DIRECTOR OF LICK OB- 
SERVATORY. 
AFTER a continuous connection with the 
Lick Observatory for 23 years and a service at 
Mount Hamilton since 1888, I have terminated 
my official relations with the Observatory, to 
take effect on December 31, 1897. My address 
after October 1st will be as below: 
EDWARD S. HoLpEN. 
SMITHSONIAN INSTITUTION, WASHINGTON., D. C. 
THE BOSTON PLANS FOR A NEW YORK BOTAN- 
ICAL GARDEN. 
To THE EDITOR OF SCIENCE: I wish to call 
your attention to an inexcusable piece of bad 
taste in the last number of Garden and Forest. 
That excellent journal was from its foundation 
edited by the late William A. Stiles, to whom 
the public park system of New York is so 
greatly indebted. It is, however, conducted, 
whatever that may mean, by Professor C. 8. 
Sargent, director of the Arnold Arboretum. 
The last number of Garden and Forest, in an 
editorial notice of Mr. Stiles, gives as his 
crowning work the following : 
“Tt was his forethought and technical knowledge 
which have modified and delayed the schemes of the 
men who in their zeal for a botanic garden are will- 
ing to deface, unnecessarily, Bronx Park, and could 
his life have been prolonged this most valuable and 
beautiful of all the rural possessions of the city might, 
perhaps, have been spared for the best enjoyment of 
the public.”’ 
It is well known that Professor Sargent’s in- 
terference with the well matured and carefully 
prepared plans for the New York Botanical 
Garden, as enlarged upon in the daily press, 
SCIENCE, 
[N. S. Vou. VI. No. 147. 
has lessened the public appreciation of an insti- 
tution so important for the scientific and gen- 
eral welfare of the City. It is commonly re- 
ported here that Professor Sargent does not 
wish New York City to possess a botanic garden 
superior to the one directed by him. This re- 
port is doubtless incorrect, but it will certainly 
not be silenced by using an obituary notice of 
a friend in the manner indicated. 
You will, I hope, excuse me from giving my 
name for publication, and will permit me to 
state that Iam in no way connected with the 
New York Botanical Garden. 
ING Wo 
NEw YorK Ciry, 
October 16, 1897. 
SOURCE OF THE FAMOUS THETFORD LIMBURGITE. 
NEARLY half a century ago Dr. Oliver Pay- 
son Hubbard, while a member of the faculty of 
Dartmouth College, discovered large boulders 
of olivine basalt in Thetford, Vt., and discussed 
their probable derivation from basaltic areas in 
Canada. 
Some of these boulders have found their way 
aS museum curiosities to Chicago, Washington, 
New York and New Haven. They are par- 
ticularly noted for their large rounded masses 
of olivine and crystailine, grayish green, glassy 
pyroxene. 
In 1894 Dr. E. O Hovey presented to the 
scientific world, through the columns of the 
‘Transactions of the New York Academy of 
Sciences,’ valuable information concerning the 
petrography of these basaltic boulders and re- 
ferred them to the limburgite division of the 
family. 
Professor J. F. Kemp has commented upon 
the striking resemblance of olivine diabase to 
these boulders, and discussed the improbability 
of a meteoric origin. 
It has constantly been conjectured that their 
source was to the northward, since Vermont is 
in a region of extensive glaciation from that 
direction, yet geological research had failed to 
reyeal their origin until last August. 
During the summer of 1896, while engaged 
in field work in stratigraphical geology, I en- 
countered many dikes of diabase rich in olivine, 
and others of the same microscopical appearance 
