PROCEEDINGS OF SOCIETIES. 
161 
next year any resident member or members of the Section should 
prepare one dozen microscopical preparations, extemporaneous or 
otherwise, representing the many different departments of micro- 
scopical work, and exhibit the same at a meeting or meetings of 
the Section, under his own apparatus and in his own way, the 
object being to test men in regard to their technological skill, he 
offering to do the same. Those competent may compare and judge 
the results. 
On motion of Dr. Morris, it was resolved that the Curator be 
authorized to purchase for the Section a Nobert's test-plate. 
San Feancisco Microscopical Society. 
The regular meeting of the Microscopical Society was held in its 
rooms, on Thursday evening, March 4, with a full attendance of 
members. President Ashburner in the chair. Messrs. Eobert Munch, 
C. Troyer, and Theo. H. Hittell, were present as visitors. 
Dr. W. F. McAllister, United States Navy, was elected a cor- 
responding member. 
The Secretary announced the reception of the recent edition of 
the ' Micrographic Dictionary,' a very valuable work for reference. 
Dr. D. Y. Dean, city chemist and microscopist of St. Louis, pre- 
sented a copy of the Seventh Annual Eeport of the Board of Health of 
that city, which contained valuable reports of microscopic investi- 
gations of meats and parasites. 
A communication from the committee appointed to receive contri- 
butions for the National Polish Museum was read, also interesting 
letters from Messrs. W. H. Walmsley, of Philadelphia, J. W. Deems, 
and Captain John H. Mortimer, of New York, corresponding 
members. 
Dr. A. Mead Edwards, of Newark, N.J., and Mr, A. F. Dod, of 
Memphis, corresponding members, favoured the Society with lengthy 
and valuable letters containing assurances of interest and assistance 
in the good work, the latter gentleman accompanying his letter with 
a very interesting paper on Mr. Tolles' new four-system immersion 
yLth objective. The notes prepared by Mr. Dod were a memorandum 
of the tests made by him in the way of comparison with other first- 
class objectives of a less angular aperture, both with central and 
oblique illumination, and various test-objects. His results point 
directly to the fact that when the low-angled objectives failed to give 
as satisfactory results as the jQth, using low eye-pieces, they were 
utterly vanquished when increased eye-piecing was applied to amplify 
the image ; and this too with central light. The generally received 
doctrine that the wide angles are only valuable for work with oblique 
light, would seem to be overthrown ; and the conclusion of Mr. Dod 
and the gentleman who aided in the test was unanimous that this 
tenth of Tolles', with the highest attainable angle of aperture, can 
meet the narrow angles in the field that has been hitherto regarded as 
peculiarly their own, and not only successfully compete with, but 
actually and undoubtedly surpass them, one and all. 
So much has been said and written on this subject that any addi- 
