PROGRESS OF MICROSCOPICAL SCIENCE. 
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becomes more than double its breadth, and the nucleus itself, also 
somewhat elongated, assumes a central position, with its long axis in 
the direction of that of the body. A tendency to constriction across 
the middle of both body and nucleus is the next change observed. 
This increases until the two halves are at last connected by a tiny 
filament only. The anterior half contains the old peristome quite 
unaltered, while in the posterior half new adoral cilia) begin to 
develop from the ordinary ciliary layer. At this stage the nucleus 
parts in two, so as to form a separate nucleus for each half of the 
body. Usually only one contractile vacuole is now found lying near 
the back portion of each half, for the anterior vacuole does not 
generally appear until the separation has been quite completed ; both 
halves of the animal gradually take on a more independent life, and, 
finally, the connecting filament gives way, and the two halves fall 
apart as distinct living beings. The anterior half, which contains 
the original peristome, is a fully-developed animal from the time of the 
separation ; but the posterior half is as yet very unlike the full-grown 
parasite, into which it in time develops. 
Bacteria in the Uterus. — Professor Waldeyer, of Breslau, records 
that he has found these in great numbers in the diphtheritic deposit 
on the inner surface of the uterus, the puriform mass from the lymph- 
vessels of the uterus and broad ligaments, the peritoneal exudation, 
both in the fluid and also in the whitish-yellow purulent fibrinous 
flakes. Haussmann formerly only found the Bacterise and vibriones 
in the lochial secretion. In the diphtheritic exudation these Bacterife 
lie between the pus-cells and those of the partly decomposed tissue 
elements. The puriform contents of the lymph-vessels consist of, 
besides the pus-cells, for the most part of Bacteria), and they are also 
found in the peritoneal exudations and flakes, mixed with pus-cells, 
young cells, and masses of fibrine, and even in the interior of the 
pus-cells. 
Opaque Illumination under High Objectives. — Dr. W. A. Johnson 
has communicated to the Microscopical Society of Illinois another 
mode of managing the above. He employs Professor H. L. Smith’s 
mode of making the objective its own illuminator ; but instead of 
the silvered reflector, thin glass disk, or reflecting prism, used by 
Professor Smith and subsequent experimenters, he employs the 
binocular prism of Wenham’s binocular. A beam of light reflected 
down the oblique body of the Wenharn binocular, the prism being in 
position as for ordinary use, is of course condensed by half the 
objective upon the object in its focus; while the other half of the 
objective and direct body of the instrument is used at the same time 
as a monocular for viewing the object. A portion of the field is 
intensely illuminated, and definition is said to be better than with 
other arrangements. — American Naturalist. 
The Internal Limiting Membrane of the Betina. — A paper on this 
subject appears in the ‘Northern Archives of Medicine.’ The author, 
M. G. Rctzius, describes peculiar supporting filaments with trumpet- 
shaped terminal disks. He has in the same journal a second paper, 
