410 



MICROBIOLOGY 



described as long and very slender, its length varying from 

 9 to 26 /A. Both extremities are pointed. The spiral forms 

 predominate but in the same preparation curved or simply 

 long straight threads were observed. They appeared singly, 



in pairs and in clumps. It 

 was difficult to distinguish 

 it in the unstained prepa- 

 ration. It stains well with 

 any of the ordinary aniline 

 dyes but does not retain the 

 (J/V Q} coloring matter after being 

 /i0 I Created by the Gram 

 ; method. 



Hindle r> has studied the 

 life cycle of Treponema 

 gallinarum. He worked 

 with spirochaetosis brought 



Spirochaetes from the f rom Brazil by Prof. Mar- 

 choux. Hindle demonstrat- 

 ed that this parasite 

 multiplied by transverse division as shown in Fig. 94. He 

 also showed the life cycle of the parasite in the fowl and tick 

 (Argas). Figure 95 is taken from his article. The various 

 steps in the life cycle of Sp. gallinarum are summarized by 

 Hindle as follows : 



"One end of a long spirochaete (a) doubles back (b), 

 the reflexed portion being closely applied to the main part of 

 the parasite. The reflexed part gradually increases in length 

 (c), all the time being closely wound round the other portion 

 of the spirochaete (b, c), and thus the two ends approach each 

 other and finally appear in juxtaposition (d). The appear- 

 ance now presented by the parasite is that of two spirochaetes 

 tightly coiled together, except that at one end of the coil the 

 two threads are continuous, being flexed through an angle of 

 180. 



"After having passed through this process, which takes 

 5 Hindle. Parasitology, Vol. IV (1911) p. 463. 



*sdra 

 Af4*ifc 



Fig. 93. 



lesions .in the diseased skin of a 

 pig. (After Dodd). 



