594 PATHOGENIC MICROORGANISMS 



by Lustgarten 1 in 1884 seemed, for a time, to have solved the mystery. 

 The Lustgarten bacillus was an acid-fast organism very similar to 

 Bacillus tuberculosis, and found by its discoverer in a large num- 

 ber of syphilitic lesions. The observation, at first, aroused much interest 

 and received some confirmation. Later extensive investigations, how- 

 ever, failed to uphold the etiological relationship of this bacillus to the 

 disease and practically identified it with the smegma bacillus, so often 

 a saprophyte upon the mucous membranes of the normal genitals. 



In 1905, Schaudinn, 2 a German zoologist, working in collaboration 

 with Hoffmann, investigated a number of primary syphilitic indurations 

 and secondarily enlarged lymph nodes, and in both lesions discovered a 

 spirochsete similar to, but easily distinguished from, the spirochaetes 



FIG. 129. SPIROCH^ETA PALLIDA. Smear preparation from chancre stained 

 by the india-ink method. 



already known. He failed to find similar microorganisms in uninfected 

 human beings. 



The microorganism described by him as "Spirochseta pallida" is an 

 extremely delicate undulating filament measuring from four to ten micra 

 in length, with an average of seven micra, and varying in thickness from 

 an immeasurable delicacy to about 0.5 of a micron. It is thus distinctly 

 smaller and more delicate than the spirochaete of relapsing fever. Ex- 

 amined in fresh preparations it is distinctly motile, its movements con- 

 sisting in a rotation about the long axis, gliding movements backward 

 and forward, and, occasionally, a bending of the whole body. Its con- 

 volutions, as counted by Schaudinn, vary from 3 to 12 and differ from 

 those observed in many other spirochaetes by being extremely steep, or, 

 in other words, by forming acute, rather than obtuse, angles. The ends 

 of the microorganism are delicately tapering and come to a point. In 



1 Lustgarten, Wien. med. Woch., xxxiv, 1884. 



2 Schaudinn und Hoffmann, Arb. a. d. kais. Gesundheitsamt, 22, 1905. 



