and Laboratory Methods. 2491 



a smooth fragment of porous soapstone ; place the stone in a saucer, the bottom 

 being covered with water ; invert a tumbler over it, and the spores will grow well. 

 Or place in the moist chamber given in the Journal. 



Some prothallia advance beyond the rest, produce antheridia and bear many 

 archegonia. Now keep the crop with little moisture for several weeks, then 

 suddenly water it and a great number of antheridia and archegonia simultaneously 

 open, and in a few hours afterwards the surface of the larger prothallia will be 

 found almost covered with moving antherozoids. 



Such prothallia as exhibit freshly opened archegonia now hold by one lobe 

 between the forefinger and thumb of the left hand, so the upper surface of the 

 prothallium lies upon the thumb; take the thinnest possible sections perpen- 

 dicularly to the surface of the prothallium. Some of these may lay open the 

 canals of the archegonia and within these, when a power of 200 to 500 diameters 

 is used, antherozoids may be distinguished. 



The Prothallium of Osmunda regalis offers peculiar facilities for study. 

 Mount in any of the following : 



1. Carbolic acid, 1 drachm; alcohol, 2 drachms; dist. water, VI ozs. Dis- 



solve the acid with alcohol, add water, boil 10 minutes and bottle. 



2. Acetate of aluminium, 1 part; dist. water, 4 parts. Is also used for 



algae, etc. 



3. Ralf's liquid, or Deane's compound. 



For further notes, see Chamberlain's Notes in Botanical Methods, Journal 

 OF Applied Microscopy ; Strasburger's Practical Botany ; Zimmerman's Practical 

 Botany Technique; Huxley and Martin's Biology. 



It is a good plan to secure a first-class mount from such workers as Miss M. 

 A. Booth, Rev. J. W. King, and Miss Dewey to use as a sample of what to 

 aim for. V. A. Latham. 



Rogers Park, Chicago, 111. 



The following is one of the best methods of staining the tubercle bacillus : 

 The small, yellow, caseous-looking points from a sputum rich in the bacilli are 

 spread out by pressure between two cover-glasses, so that a fairly thin film remains 

 on each, when they are carefully slipped one over the other until they come apart. 

 Thoroughly dry the covers, protecting them carefully from dust, pass rapidly 

 three times through the flame of a spirit lamp, care being taken not to scorch 

 the film, then float film-face downwards, on the staining solution, which has pre- 

 viously been filtered into a watch-glass. The stain should consist of saturated 

 alcoholic solution of basic fuchsin, one part ; absolute alcohol or rectified spirit, 

 ten parts ; carbolic acid solution (5 p. c), ten parts. Leave the preparations in 

 the watch-glass for twelve to twenty-four hours, unless time is an object. In the 

 latter case heat the fluid gently until vapor is given off, then drop the films on 

 the surface, and leave them for three to five minutes only. Next transfer the 

 covers to an aqueous solution of sulphuric acid (25 p. c), and when decoloriza- 

 tion is complete, as evidenced by the pink coloration not returning when the 

 specimens are plunged into a bowl of tap-water containing a single drop of 

 ammonia solution, thoroughly rinse in the slightly alkaline water and counter- 

 stain in an aqueous solution of methylene blue. Finally, wash in water, carefully 

 dry and mount in Canada balsam. The bacilli should stand out as bright red 

 rods on a blue background of cells, etc. — Practitioner. 



