34 
about one inch out of the true line ; grind off the teeth of the file; 
retemper the blade; put on a strong wooden handle, and geta 
leather case made for convenience of carriage. - 
Or, again, such an instrument may readily be made de novo. It — 
_ Should be, blade and handle included, about eleven inches long, and 
each side of the triangle where the blade joins the handle seven- _ 
eighths of an inch wide. Some of the advantages of this narrow — 
but strong instrument are that it will follow the roots we wish to : 
extract without cutting them, and into crevices of rocks where a _ 
broader tool could not be inserted or would be liable to break. It 
was the favorite instrument of that eminent botanist, Philip Barker 
Webb, in his Alpine excursions. [See Collector's Handbook, by 
the Rev. W. W. Spicer, M. A., London, 1869, p- 158. ] 
In the accompanying wood-cut, 2 
the blade is not quite enough — 
curved. F. J. B. 
61. Note from Dr. Engelmann—I have now had Prof. Wood’s specimen 
of Opuntia from Westchester Co., one from New J ersey sent by Mr. 
Meehan, and a third from New England, probably Massachusetts, — 
furnished by Prof. Gray, side by side in cultivation with our Missourl 
and Illinois O. Rafinesquii. It is certainly less spiny, and sometimes 
the flower is smaller than in our plant, but the deep green colour, © 
the long spreading leaves, and the bright brown bristles, especially 4 
on the older joints, on which they increase in number and length — 
to considerable bunches, are characteristic of the plant. With them 
I have growing the true 0. vulgaris sent by Dr. Schott from the 
banks of the Potomac and probably not found north of Chesapeake 
Bay,with thicker light green joints, shorter, thicker, more adpressed , 
leaves, and small bunches of short thin greenish yellow bristles. — 
This is the plant which is cultivated in Europe under that name 
and has become naturalized in Northern Italy and which I have 
described and figured as such in Vol. 4, Pacif. R. Reports. 
_ Mr. H. Gillman of Detroit has found in the neighborhood of that 
city Spirodela polyrrhiza in bloom. His specimens are stouter thaD — 
the Staten Island ones, and all the flowers I could examine, 512 
number, were 2-ovulate, the ovules joining at the erect funiculus, — 
and fully anatropous, while, in that case, the single ovules were 
hemi-anatropous, the specimens being, as was suggested at the 
time, depauperate otherwise, in the structure of the anthers ete 
both specimens are identical. | 
You may have heard that the Germans, or rather the Rhine-— 
landers were quite excited last spring about the discovery of the 
aromatic Asperula odorata in America, an herb which is highly prized — 
for the flavor it imparts to wine. I obtained specimens and found — 
them to be Galium triflorum, Mchx. Upon my publishing this for 
the information of my German friends, the true Asperula odorat 
was sent to me by the editor of the N. Y. Staats-Zeitung yout 
city, as having been found in the woods near Brooklyn. There ca? 
be no doubt of my having seen fresh specimens of the true plant. 
How can that be? Has it been planted and naturalized there, of 
