350 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
MICROSCOPY. 
a. Instruments, Accessories, &c.* 
(1) Stands. 
Meyer’s Microscope-Stage with Iris-Diaphragm.f — Dr. W. Behrens 
refers to the various contrivances which have been tried for passing from 
condenser illumination to diaphragm illumination, and describes the 
method adopted by the firm of Meyer & Co., in which an iris-diaphragm 
is attached to the under side of the stage. 
The aperture of the stage, which is of the Zeiss type, is larger than 
usual (23 mm. in diameter). The short cylinder with the iris-diaphragm 
is fixed to the under side of the stage by a circular plate, with central 
aperture, which is screwed to the stage. This plate is cut away on one 
side to make room for the handle of the diaphragm, which projects on 
the right side of the stage. 
Beneath the diaphragm is the condenser system, which can be turned 
to one side when the stage-diaphragm is to be used. 
* This subdivision contains (1) Stands ; (2) Eye-pieces and Objectives ; (3) Illu- 
minating and other Apparatus; (4) Photomicrography; (5) Microscopical Optics 
and Manipulation ; (6) Miscellaneous. 
t Zeitschr. f. wiss. Mikr., xii. (1896) pp. 292-5. 
