1880 ] Microscopy. 465 
discovered the reason why the web is plain in some parts and 
beaded in others, the radial threads being continuous while those 
which form the concentric circles are beautifully beaded. ‘ When 
emitted by the spider, the web is in avery viscid state, and I 
noticed that when the whole weight of the spider was upon the 
web, and the thread was fastened off quickly, it was not beaded ; 
but when by some chance the spider had slightly relaxed the ten- 
sion before fastening it off, | observed a slight quiver pass through 
the thread, and upon examining it with a magnifier, I found that 
it was beaded from end to end. 
Woop-FIBRES FOR PAPER-MAKING.—Mr. Galloway C. Morris has 
contributed to the Postal Club a special box of wood fibres pre- 
pared in a form suitabie for paper pulp. They were prepared by 
boiling under pressure in caustic alkali in order to destroy every- 
thing but the cellulose, and the peculiar wood fibres of the plants 
selected are completely isolated and well shown. Not only do 
the preparations show soft woods such as poplar, pine and buck- 
wheat, but also such harder woods as hickory, rosewood and 
ebony. 
CLEANING Cover-GLAssEs.—Dr. R. U. Piper, of Chicago, has 
invented a very simple method of cleaning cover-glasses without 
breaking them. Upon a glass plate 2 x 3 inches are cemented, 
in the form of a V, two thin strips of glass. A cover-glass may 
be laid upon the glass plate inside of the V and cleaned by rub- 
nig Poy being held in position from slipping by the sides of 
the V. 
SPODUMENE.—An excellent paper on this subject, reprinted from 
the Annals of the New York Academy of Sciences, by Alexis 
A. Julien, contains interesting discussions of the microscopical 
characteristics of this mineral and its alterations. They can 
oe oily studied only in connection with the accompanying 
piate. 
THE MICROSCOPICAL APPEARANCES OF THE VALVES OF DIATOMS. 
—In a paper on this subject, reprinted from the Annals of the 
Belgian Microscopical Society, Mr. Julien Deby, vice-president 
of the society, gives a very interesting study, accompanied by 
diagrammatic illustrations, of the proper interpretation, in re- 
Spect to their physical structure, of the microscopical appearances 
of some of the more puzzling species of diatoms. 
THE AMERICAN JourNAL oF Microscopy. — This monthly, 
whose publication was temporarily delayed during a considerable 
Portion of last year, has now been brought up to date, and the 
current numbers are being issued regularly and promptly. Last 
year’s numbers, Vol. 1v, have been issued as a bound volume, and 
constitute, at a slight cost, a book full of interesting glimpses of 
the daily progress of this branch of science. 
