124 THE ROYAL SOCIETY OF CANADA 



Motility. — The organism is motile when in the form of rods. 

 In the globular form there is marked Brownian movement but no true 

 motility. No movement of the symplasm was observed. 



The motility of the cylindrical rods is sluggish, a side to side 

 movement, one end often deeper in the hanging drop than the other. 

 Motile rods have been obtained from both liquid and solid media and 

 from fish. 



The flagella are two in number, attached one at each pole. 

 They were most difficult to stain, owing to conditions already men- 

 tioned, but although faintly stained the lophotrichous nature of this 

 organism was established. 



The mordant used was made from 



Tannic acid 20 per cent. — 10 parts, 

 Sat. Sol. Iron Sulphate — 8 parts, 

 Sat. Ale. Sol. Gentian Violet — 1 part, 

 filtered on the slide previously fixed in absolute methyl alcohol. 

 After remaining on the preparation from 5 to 15 minutes, the mordant 

 was washed off with tap water, and then the film was stained by hot 

 aniline carbolic gentian violet (Kiitscher) for 2-5 minutes, washed, 

 dried and examined. 



Staining Reactions. — ^The red organism is difficult to stain. 

 Preparations cannot be made in water, as immediately plasmoptysis 

 occurs, forming a viscous mass which can be pulled out several inches. 

 Consequently all preparations must be made in 16 per cent, to 20 

 per cent, salt solutions. These are allowed to air dry, when the film 

 is covered with a layer of salt crystals. Absolute methyl alcohol is 

 then poured on and allowed to remain for 2-5 minutes, renewing the 

 alcohol from time to time when necessary. Giemsa's solution is then 

 added to the alcohol on the slide and allowed to remain on for 10-30 

 minutes. The slide is then washed in a beaker of tap water, dried 

 and examined. Instead of Giemsa, anilin carbolic gentian violet 

 may be used. These two stains gave the best results of all those 

 tried. The organism is gram negative. 



The usual difficulty of nomenclature arises in placing this 

 organism in any system of bacterial classification. 



Buchanan's (32) genus Pseudomonas does not fit exactly for red 

 pigment is not mentioned, and organisms producing this colour are 

 included in the next described genus Serratia; this genus is described 

 as having peritrichous flagella, the type species being Serratia mar- 

 cescens, Bizio better known as B. prodigiosiis. The genns Bacterium 

 does not apply as the type species is B. coli Escherich. 



