704 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
in regard to the chemical action of these colours was removed by a solu- 
tion containing basic fuchsin and acid green. The result was a reversal 
of the colours ; the chromatin and the yolk-nucleus were stained red, 
and the cytoplasm green. Other differential stains were used, and all 
gave similar results. 
Teichmann’s Cold Injection.* — Prof. J. Kollmann explains the 
excellencies of this method. The red injecting mass consists of powdered 
chalk 500 grm., red lead 100 grm., thick linseed oil 80-90 ccm., to which 
carbon disulphide is added in proportions varying with the calibre of 
the vessels to be injected. The blue mass consists of zinc white 450 grm., 
ultramarine 25-30 grm., and boiled linseed oil 60-75 ccm., dissolved in 
carbon disulphide or sulphuric ether. For injecting the lymph- vessels 
in white, the mixture is zinc white, thickened linseed oil, and sulphuric 
ether. The advantages over wax injection are great. 
(5) Mounting, including Slides, Preservative Fluids, &c. 
Distortion of Sponge-cells in Preservation.! — Mr. G. Bidder gives 
the results of a few measurements on sponge-cells which may be of 
interest to those who study histology on preserved materials of other 
groups as well as of sponges. All the sponges were preserved in osmic 
acid for one hour ; followed by alcohol, benzol, and paraffin, and 
measurements were made of the collar-cells in six series of sections which 
may be labelled A to F. In C, D, and F, the change from water into 
absolute alcohol was effected by dialysis. In all but B, the change from 
absolute alcohol into benzol was made in tbe same way. A was the 
only sponge preserved in * 5 per cent, instead of 1 per cent, osmic acid. 
It alone was decalcified, it alone was stained in bulk with borax-carmine, 
and it alone was cut by the ribbon method. The distal expansion and 
fusion of the collars known as “ Sollas’s membrane ” appeared plentifully 
in the paraffin sections A, B, C, and F ; scarcely at all in D and E, but it 
was not present in the living sections examined from any of the sponges. 
It was found that the average cubical contraction of the cells is about 
one-half of their living dimensions. The best series of sections D and 
the worst A show respectively the following ratios in their dimensions to 
those of life. 
In Series D. In Series A. 
Collar width *83 *5 
Basal width *88 *7 
Height *8 * 5 
Height of collar 10 1*0 
Deduced ratio of volume of cell to that in life . . * 55 * 2 
Deduced mean linear contraction ratio .. .. ’82 *6 
The difference of the best two series of sections from all the others 
lies in the uniformity of their contractions. 
We find, then, two principal phenomena due to the transference of 
cells through osmic acid, alcohol, and benzole, into paraffin, and finally 
Canada balsam. (1) There is a reduction in the total volume of the 
cell, which apparently cannot be avoided, corresponding to a mean linear 
contraction of about 5 to 4 in the best preparations, and 5 to 3 in the 
* Yerh. Anat. Ges., ix. pp. 77-88. 
f Quart. Journ. Micr. Sci., xxxviii. (1895) pp. 33-8. 
