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PROGRESS OF MICROSCOPICAL SCIENCE. 
consist of a mass of protoplasma, sharply defined on every side, 
except where it is continuous for a scarcely perceptible distance into 
the processes. The nucleus is flattened. The processes become 
very fine, glistening, and thread-like almost immediately after leaving 
the cell, and, by dividing and anastomosing with the processes of 
other cells, form a rich and very delicate network. 
2. It sometimes happens, although only in rare instances, that, in 
gold preparations, fine dark lines extend between the nuclei, and 
correspond in outline and course with the processes seen in the 
aqueous humour ; and it is then evident that they are surrounded by 
the dark-coloured tracts which form the ordinary network seen in 
gold preparations, and which correspond, in outline and varying 
degree of development in different animals, ages, and pathological 
conditions, with the corneal spaces. 
3. Similar appearances to those described in paragraph 1 are seen 
in sections of cornea which have been five to ten days sealed up in a 
10 per cent, solution of common salt. 
4. The quadrangular and long narrow flat cells shown by the 
author to exist in the cornea by means of a saturated solution of 
potash, are also rendered visible by the above method. They are 
best seen in oblique sections, from which, after two to five days, they 
fall out singly and in rows. A row of the long narrow cells is often 
seen to terminate in quadrangular cells at either end. These cells 
have a perfectly hyaline appearance ; their nucleus has a very faint 
yellowish tinge, and projects beyond the surface of the cell. 
In exceptional instances, in the uncut cornea of the frog, the 
long flat cells may he seen, after several days’ maceration, lying on 
the primary bundles. 
5. In tendon, flat masses of cells are found, on the third to fifth 
day, lying on the edge of the preparation and free in the fluid. The 
cells are accurately fitted to each other, after the manner of an 
epithelium. In the tendo A chillis of the frog they are seen of three 
sizes : (a) large cells, corresponding to the flat cells seen on the 
surface by nitrate of silver ; ( b ) smaller quadrangular cells, similar 
in size to those described by Kanvier, and which have been described 
by the author as investing the secondary and tertiary bundles in 
double layers ; and ( c ) long, narrow, flat cells, similar to those 
described by the author as being isolable by potash, and as covering 
the primary bundles. 
The masses of the cells of the surface, and of the secondary and 
tertiary bundles, can be usually seen to consist of a double layer 
separated by a very thin transparent medium. 
6. The perimysium and neurilemma are respectively represented 
by a double layer of quadrangular and hexagonal cells, identical in 
general appearance with an epithelium. Between the two layers 
there is a thin transparent medium. 
7. From the neurilemma of the sciatic nerve of the frog, when 
cut in narrow longitudinal strips, after a few hours, branched cells of 
different types of form are seen isolated in the fluid near the cut 
edges. These cells are of two well-marked general types. In one 
