18 THE AMERICAN MONTHLY [January, 
such evidence to the contrary. If you or any of your numerous readers can set me 
right in the matter, I shall be greatly obliged. . 
Respectfully, HEnrRY MILLs. 
162 Fargo ave., Buffalo, N.Y. 
MICROSCOPICAL SOCIETIES. 
SAN FRANCISCO MICROSCOPICAL SOCIETY. 
At the regular semi-monthly meeting, Nov. 24, 1886, Mr. Wickson stated that recent 
experiments had shown quite conclusively that the recently-observed insects of the genus 
Psocus, formed on scale-infested laurel trees, would not, unfortunately, attack the scale 
insect itself. 
Specimens of an Australian Polyzoan, Bzce//aria ciliata, were shown by Mr. Howard, 
who also exhibited an alga ( 77ichodesmium sp.) found floating in immense quantities 
in the Pacific. It consists of red-like filaments, transversely striated and ofa light olive- 
green color. The average length and diameter are, respectively, .o15 and .0003 of an 
inch. One peculiarity of growth is that the filaments arrange themselves in bundles of 
about twenty-five to fifty. This minute plant forms a considerable part of the food of 
the right whale, and is, in fact, known to many mariners as ‘whale-feed.’ The process 
of spore formation does not seem to have been observed as yet. 
Some remarkably fine examples of insects, preserved in amber and in fossil copal, 
were shown by Prof. Hanks. 
Dr. Montgomery exhibited a number of interesting slides, illustrative of the minute 
structure of the eye. Alum-carmine had been used as the staining agent, and the nuclei 
of the various cells were thereby very clearly defined. 
A ‘Holman Life Slide,’ containing an unusually rich collection of pond organisms, 
was shown by Mr. Payzant.. Germinating gonidia of Vawcheria, many Desmids and 
other algee, Arcellae, Amcebee, and other Rhizopods and innumerable infusoria, were 
observed. Noteworthy among the latter were several examples of a species belonging 
to the beautiful genus Zfzs¢y/’s. As the individuals each showed a peculiar band or 
collar just below the posterior margin, a characteristic apparently hitherto undescribed, 
the little animals are quite probably specifically new. 
Dr. Ferrer promised a demonstration, in the near future, with the new Zeiss photo- 
micrographic apparatus recently received, and the meeting adjourned. 
A. H. BRECKENFELD, Sec’y. 
O 
SAN FRANCISCO, CAL. 
The San Francisco Microscopical Society held its regular semi-monthly meeting 
Dec. 8, 1886, at the rooms of Dr. Henry Ferrer. Vice-President Wickson occupied 
the chair, and explained that the meeting had been called for the special purpose of _ 
examining the new Zeiss photo-micrographic camera and stand. 
Dr. Ferrer then briefly described the salient points of the instrument. A special 
microscope stand is provided, having an unusually short and thick body-tube. _It rests 
upon a large and firm adjustable tripod foot, and is fitted with a roomy mechanical 
stage, and with a sub-stage for carrying an Abbe’s condenser or other accessories. The 
coarse adjustment is made by the usual rack and pinion. The camera itself is of very 
large size, permitting a range of nearly eight feet from the object, when fully extended. 
Its front bears a metal sleeve or nose-piece which racks out to the body-tube of the 
microscope, forming a light-tight connection with it. In addition to the ordinary 
ground-glass focusing plate, one of clear plate-glass is provided, furnished with a 
focusing-glass sliding vertically between brass guides. By this means an exceedingly 
delicate adjustment can be obtained. The fine adjustment is regulated by a milled head 
attached to a long brass rod, which latter translates the movement to the fine adjustment 
micrometer screw by means of two very ingenious universal joints. The illumination 
used on this occasion was a very large oil lamp, with a bull’s-eye condenser interposed 
between it and the Abbe condenser in the sub-stage, and for work with low powers. Dr. 
Ferrer stated that he had found the light fairly satisfactory, but he hoped to improve upon 
it by using the electric light in some way, and several patterns of incandescent lamps 
were now being tested by him. He also stated that he had ordered the best obtainable 
heliostat, for photographing with sunlight, and he therefore hoped soon to be in a position 
to do excellent work with high amplifications. Hitherto he had dispensed with the 
oculars, using only the objectives and specially-constructed amplifier, but he intended 
