BACILLUS TYPHOSUS. 409 



forms may occur together. Its breadth remains toler- 

 ably constant. Its morphology presents little that 

 will aid in its identification. (See Fig. 71.) It stains a 

 trifle less readily with the aniline dyes than do most of 

 the other organisms. It is very actively motile, and 

 when stained by the special method of Loffler (see 

 this method in chapter on Staiaing) is seen to possess 

 very delicate locomotive organs in the form of fine, 

 hair-like flagella, attached in large numbers to all parts 

 of its surface. (See Fig. 72.) These flagella are not 

 seen in unstained preparations, nor are they rendered 

 visible by ordinary methods of staining. 



In patients suffering from typhoid fever the organ- 

 ism has been found during life in the blood, urine, and 

 faeces, and at autopsies in the tissues of the spleen, liver, 

 kidneys, intestinal lymphatic glands, and intestines. 



Gelatin Plates. — Its growth, when seen in the 

 depths of the medium, presents nothing characteristic, 

 appearing simply as round or oval, finely granular 

 points. On the surface it develops as very superficial, 

 blue- white colonies, with irregular borders. They are 

 a little denser at the centre tlian at the periphery. 



Fig. 73. 



Colony of baeSlus lypJiosus on gelatin. 



When magnified, the colonies present wrinkles or folds, 

 which give, to them, in miniature, the appearance seen 

 in the relief maps made to represent mountainous dis- 



