1889.] MICROSCOPICAL JOURNAL. 155 



tractile vacuole, if visible, and watch its pulsations. 3. The nucleus 

 which maybe made more distinct by adding a drop of acetic acid {1%) 

 to the preparation, or staining with magenta. The magenta stain is 

 made bv dissolving .6 grm. crystallized magenta (rosein) in r litre 

 water, x\dd 6 cc. absolute alcohol. 



D. Add to one of the drawings the nucleus, the contractile vacuole, 

 also the food vacuoles, and any foreign substances which may be present. 



£. Look for encvsted AmcEboe and for the Amoebte in process of 

 division bv transverse fission. 



J-^. Feed with indigo or carmine, or other finely powdered pigment, 

 and note that food is taken in at all parts of the surface. 



Staining Nuclei of Protozoa. — Fix on a slide by means of a drop 

 of alcohol drawn under the cover. Then draw in water, then saturated 

 solution of picro-carmine. and then, after a few minutes, glacial acetic 

 acid. Glycerin being then added, a permanent mount is made. In- 

 stead of alcohol, exposure for one minute to the vapor of a \% solution 

 of O, O4 mav be used for fixing ; but the action of the picro-carmine 

 must be prolonged. I have seen and used it for steutor, kondylostoma, 

 spirostomum. etc., also for protophyta, volvoeina, fungi, etc. The par- 

 ticular object is to demonstrate the nuclei. 



Staining -jjith Methyl en- Blue. — (Certes, Ibid. ,^2, 2d seri., p. 464.) 

 This stains living protoplasm. Place a drop of alcoholic solution on a 

 slide and allow to evaporate. When evaporation is nearly complete, 

 add a drop of the liquid containing the organisms. As soon as the 

 staining is complete (which is very quick) the drop must be caused to 

 flow away from the spot where the crystals are deposited, and may be 

 covered and examined. 



Mounting Amcebce. — I use a 2% solution of chromic acid, and allow 

 it to act for 2 or 3 minutes, and follow by successive drops of water, 

 7o"o alcohol, 90 "-0 alcohol, and water. Then stain preparation for i^ 

 to 3 hours in a moist chamber with a drop of Weigert's picro-carmine. 

 Wash out with 7o"o alcohol, follow with 90%, then absolute alcohol, 

 clove oil, and balsam. 



Bibliography. — Huxley & Martin's Biology. IMarshall & Hurst's 

 Practical Zoology. Sedgwick & Wilson's Biology. AIcAlpine's 

 Biological Atlas. J. B. Howe's Biological Atlas. A?n. Monthly 

 Micros, yournal. vol. 9, p. 91. 



Ann Arbou, Mich., June i6, 1889. 



Portable Microscope. — Dr. Ludwig Klein, of Freburg, Germany, 

 has devised a portable microscope for use in field collecting of algie or 

 other microscopic material. Much good material is lost, and much 

 poor material is saved, because of tiie difiiculty of microscopic exami- 

 nation on the spot ; the laboratory microscopes being obviously unfit 

 for field work. His instrument is a collar carrying a tube into which 

 anv objective can be screwed, a stage and a sub-stage mirror, all fastened 

 through a device for clamping them to an ordinary walking stick. The 

 stand without objective or oculai's costs 25 marks, or about $5.00. 



Paste. — A good paste for paper on glass or metal is made by dis- 

 solving ^ oz. of gum tragacanth and 2 ozs. of gum acacia in 4 ozs. ot 

 water, straining, and adding 2 ozs. of glycerin containing 7 grains of 

 thymol as a preservative. Then make up to a pint with water. — H. 



