Jan. 1S09.] BOTANICAL SOCIETY OF EDINBURGH 159 



Notes on Micro-Methods, By Alex. Lundie, Botanical 

 Department, The University, St. Andrews. 



(Communicated 12th January 1899.) 



1. METHOD OF MOUNTING FUNGI IN GLYCERINE. 



The difticulties usually encountered in mounting fungi, 

 like Eurotium, etc., are the expulsion of air from the 

 preparations, and the proper teasing out of the filaments. 



When the conidiaphores are ripe, and conidia are being 

 shed, it is impossible to wet the fungus completely with 

 water. Absolute alcohol, however, wets it, but chloroform, 

 which has less surface tension, wets it more easily, and 

 penetrates all through the mycelium, leaving little air 

 entangled even in the sterigmata. 



If a piece of Eurotium be placed on a slide, wetted with 

 chloroform, strong glycerine added, and covered with a 

 coverslip and heated over a Bunsen flame, the chloroform 

 boils off rapidly and drives out the last traces of air. The 

 bubbles of chloroform vapour, in passing out, scatter the 

 hyphte and tease out the preparation, without breaking 

 it up, as is done when needles are used for mechanical 

 teasing. 



2. PHOTO-CHEMICAL METHODS OF STAINING 

 MUCILAGINOUS PLANTS. 



Staining by Chromatype Method. — A saturated solution 

 of potassium dichromate, mixed with one-twentieth of its 

 volume of saturated cobalt nitrate solution, is used. In 

 the original method for photographic work, nickel sulphate 

 was recommended — not cobalt nitrate. It was said to 

 make the prepared paper more sensitive to light. 



A piece of an alga, Batracliospcriimm, for example, is 

 suspended in this mixture in a glass tube, and exposed to 

 diffuse daylight for thirty minutes. It is then transferred 

 to a slide, and treated with silver nitrate solution, and 

 again exposed to light for five minutes. The nitrate is 

 now removed, and ammonium chloride solution is added 

 and allowed to remain until all the chroraate has become 



