MOELLER'S METHOD FOE STAINING SPORES. 147 



By another process the cover-slip is floated, bacteria 

 down, upon the surface of freshly prepared Koch-Ehrlich 

 solution of fuchsin contained in a watch-crystal. This is 

 then held by its edge with the forceps about 2 cm. above 

 a very small flame of a Buusen burner, care being taken 

 that the flame touches only the centre of the bottom of 

 the crystal. After a few seconds the crystal is elevated 

 gradually until it is about 6 to 8 cm. above the flame, 

 then it is slowly moved down to the flame again, and 

 this up-and-down movement is continued until the stain- 

 ing fluid begins to boil. As soon as a few bubbles have 

 been given off it is held aside for a minute or two and 

 the process of heating is repeated. When the boiling 

 begins the crystal is held aside again for a minute or 

 two. The crystal is heated in this way for about five 

 or six consecutive times. When the fluid has stood for 

 about five minutes after the last boiling, the preparation 

 is transferred, without washing in water, into a second 

 watch-crystal containing the following decolorizing solu- 

 tion : 



Absolute alcohol 100 c.c. 



Hydrochloric acid . . , 3 c.c. 



In this solution it is placed, bacteria up, and the 

 vessel is tilted from side to side for about one minute. 

 It is then removed, washed in water, and stained with 

 the methylene-blue solution. The spores will be stained 

 red and the body of the cells will be blue. 



MOELLER'S METHOD FOR STAINING SPORES. A 

 method that has recently been published by Moeller is 

 designed to favor the penetration of the coloring mate- 

 rial through the spore membrane by macerating the 

 spores in a solution of chromic acid before staining 

 them. It is as follows : 



