ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 893 



the protoplasm itself. M. Olivier also attempted to cause a fluid, 

 capable of colouring the protoplasm, to penetrate under gentle 

 pressure into the organs ; transverse sections were then made. The 

 injection i-arely succeeded ; but when it took place in a fairly regular 

 manner, this jirocess led to a result identical with the preceding. 



Eau de Javelle as a Medium for Clarifying and Dissolving 

 Plasma.* — Dr. F. Noll finds that eau de Javelle (an alkaline hypo- 

 chlorite solution) destroys and then dissolves the whole of the plasma 

 of the cells in preparations which have been preserved in alcohol. A 

 similar, but more or less imperfect solution of the plasma-contents 

 occurs in tissues which have been treated with glycerin, Miiller's 

 fluid, picric or chromic acid. It is not necessary that alcohol should 

 be present during the operation of the reagent ; if a drop of the water 

 is placed on a section made through young cells rich in plasma, this is 

 soon dissolved, with development of small bubbles of gas. If the 

 action takes place in the open air, a soft pellicle quickly forms on the 

 drop, consisting of calcium carbonate, which can be readily dissolved 

 in acetic acid. The formation of this pellicle can be prevented by 

 placing a cover- glass over the drop, under which the process can be 

 studied step by step. In a very short time, usually 3-4 minutes, the 

 plasma is converted into a clear fluid. When the section is suf- 

 ficiently clear, it is washed in water, so as to remove the bubbles of 

 gas. The superfluous granules of calcium carbonate are removed by 

 acetic acid, and the section is then ready to be placed in glycerin. 

 The water acts on cuticular membranes in the same way as Schultze's 

 macerating fluid, but only slightly and after some time (1 hour or 

 more). Calcified membranes should be first treated with acetic acid 

 to dissolve the mineral constituents, washed, and treated with the 

 water in the usual way. Starch-granules swell in the water, so as to 

 become invisible. 



Cocaine for Mounting Small Animals.j — Prof. J. Richard de- 

 scribes a new way of fixing Hydroids, Bryozoa, &c., in an expanded 

 condition, which is as follows. A number of the animals are placed in 

 a watch-glass with 5 c.cm. of water when they are fully expanded. A 

 1/2 per cent, solution of chlorhydrate of cocaine is added drop by drop 

 till it forms a fifth part of the entire fluid. Half a c.cm. of the drug is 

 then added, and the animals become so completely fixed that it is 

 necessary to touch them very roughly with a needle in order to induce 

 them to contract ; ten minutes after, they are quite dead, and can bo 

 mounted in the ordinary way. This reagent is superior to all others, 

 because it requires no delicate manipulation ; it is not certain yet 

 whether its effect upon marine animals is equally strong in all cases. 



Preparing Tissues to show Cell-division.t — Dr. C. Rabl objects to 

 Flcmming's chrom-osmic-acetic acid mixture, on the ground that the 

 preparations soon become darkened ; and to the 1/2 or 1/3 per cent. 

 solution gold chloride, that in summer reduction takes place and the 



• Bot. Centralbl., xxi. (1885) pp. 377-80. 



t Zool. Anzoif,'., viii. (188.'5) pp. 332-3. 



X Morpliol. Jahrb., x. (1S8I) pp. 214-330 ((> pis.). See this Journal, ante, p. 217. 



