CHAPTER XXII. 



Typhoid fever — Study of the organism concerned in its production. 



The organism, discovered by Eberth and by Gaffky, 

 which is recognized as the etiological factor in the 

 production of typhoid fever, may be described as 

 follows : 



In patients suffering from this disease it has been 

 found during life in the blood, urine, and feces, and at 

 autopies in the tissues of the spleen, liver, kidneys, 

 intestinal lymphatic glands, and intestines. 



It is a bacillus about three times as long as it is broad, 

 with rounded ends. It may appear at one time as very 

 short ovals, at another time as long threads. Its breadth 

 remains tolerably constant. Its morphology presents 

 nothing that will aid in its identification. It stains a 

 little less readily with the aniline dyes than do mo.st of 

 the other organisms. It is very actively motile, and 

 when stained by the special method of Loffler (see this 

 method in chapter on Stainings) is seen to possess very 

 delicate locomotive organs in the form of fine, hair-like 

 fiagellse, which are given off in large numbers from all 

 parts of its surface. These flagellse are not seen in 

 unstained preparations, or are they rendered visible by 

 the ordinary methods of staining. 



Gelatin Plates. — Its growth, when seen in the 

 depths of the medium, has nothing characteristic, ap- 

 pearing simply as round or oval, finely granular points. 

 On the surface it develops as very superficial, blue-white 



