ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 147 



from the paraffin by means of xylol and alcohol, and then stained for 

 about three minutes in a solution of acid-fuchsin (10 grm. of the dry 

 stain dissolved in G6 grm. of water and 33 c.cm. of absolute alcohol added), 

 and afterwards differentiated in a solution of picric acid (10 grm. picric 

 acid, 150 c.cm. absolute alcohol, 300 c.cm. water). Over-action of the 

 picric acid is prevented by the absolute alcohol. From the spirit the 

 sections are transferred to bergamot oil and xylol. The mica-scale is 

 not detrimental beneath the cover- glass, provided the preparation lies 

 above it. Thus stained, the cell-granules are to be examined with oil- 

 immersion lenses, weak ocular, and a powerful illumination. For 

 demonstrating the granules by means of this staining process, fixation 

 methods which the author is to describe in future are necessary. 



Methods of Preparing Muscle for investigation.* — Mr. C. F. 

 Marshall, in his investigations into the distribution of striped and un- 

 striped muscle (see this Journal, 1887, p. 935), chiefly made use of 

 Melland's method of gold-staining. The gold stains and renders evident 

 the intracellular network of most cells, and especially the network of tbe 

 striped muscle-cells. Melland's method consists in placing the muscle 

 in 1 per cent, acetic acid for a few seconds ; then in 1 per cent, gold 

 chloride for thirty minutes, and then in formic acid (25 per cent.) for 

 twenty-four or forty-eight hours in the dark. For more delicate organ- 

 isms, such as Hydra or Daphnia, and the heart muscle of invertebrates, 

 one hour's immersion in formic acid, exposed to strong sunlight, is the 

 best treatment, as longer immersion in formic acid may lead to disintegra- 

 tion of the tissues. Control preparations were made with osmic acid. In 

 many cases the examination of fresh tissues was useless ; the special 

 action of the gold-staining is to soften the fibre and so swell it out, 

 while at the same time staining the network. With regard to this 

 reagent, it is to be noted that the results obtained are somewhat un- 

 certain ; care must be taken with the time of action of the acetic acid. 



Permanent Preparations of Tissues treated with Potassium 

 Hydrate.| — Mr. B. L. Oviatt uses a solution of potassium hydrate of 

 from 36-40 per cent, (potassium hydrate 40 grams, water 60*00); then 

 this is replaced by a saturated aqueous solution of potassium acetate. 

 Then add the staining agent, and then glycerin as a permanent medium. 

 Heart muscle treated in this way five months ago is as perfect as ever. 



Preparing Sections of Bone.J — Dr. G. Chiaragi decalcified a strip 

 of quite fresh bone (bird) in picro-nitric acid diluted with two volumes 

 of distilled water and then placed it in spirit of increasing strength. 

 The sections were then immersed for some minutes in a 1 per cent, 

 solution of eosin and afterwards washed in a 3 per cent, hydrate of 

 potash solution. The eosin stained the bone-cells and their processes, 

 the rest of the bone being uncoloured. In order to fix the eosin, the 

 sections were washed in a 1 per cent, alum solution. The sections were 

 mounted in the alum solution. 



Method of investigating Cristatella.§— Herr M. Verworn gives an 

 account of his methods of working with Cristatella. The colonies were 

 treated with 10 per cent, chloral hydrate solution for the purpose of 



* Quart. Journ. Micr. Sci., xxxviii. (1887) pp. 81-2. 

 t St. Louis Med. and Surg. Journ., liii. (1887) p. 289. 

 % Bull. See. Cult, Sci. Med. Siena, iv. (188(3) Noa. 8 and !_». 

 § Zeitschr. f. Wiss. Zool., xlvi. (1887) pp. 100-1. 



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