408 BACTERIA IN INFECTIOUS DISEASES. 



or sixth week; if found then they present evi- 

 dence of having undergone retrograde change. 



The typhoid germ of Letzerich is a micrococcus, 

 isolated, in colonies, or in chains, very dissimilar 

 to those of diphtheria and of infectious pneumonia, 

 but which by cultivation may reach twice or three 

 times the size of the micrococci of the last men- 

 tioned diseases. 



Klebs describes his Bacillus typhosus as large- 

 sized filaments of 50 //, in length and 0.2 //, in 



breadth, without 

 segments or rami- 

 fications. When 

 the spores make 

 their appearance 

 the filaments may 

 reach 0.5 JJL in 

 breadth. The 

 spores are ar- 

 ranged in a line, 

 and very close 

 together. Before 



At- / J 



they are formed, 



Section of typhoid lung ; fresh; treated with mixture 



of glycerine and glacial acetic acid. Siebert's the baCllll CXlSt 



as short rods (see 

 Figs. 23, 24, and 25). 



The morphological characters of the bacillus of 

 Eberth are shown in IJig. 26, which is copied from 

 his paper, referred to in bibliography. 



When these bacilli are present in great numbers 

 they have the appearance of masses of micrococci. 



