(Trypanosoma) Balbiauii atid S. anodontge. 405 



fd'ed ivet with osmic vapour. Other fixatives used were 

 Flemniing's solution, corrosive sublimate and alcoliol, and in 

 the case of some dried smears pure methyl and ethyl alcohols. 

 The preparations were usually mounted in cedar-wood oil 

 or balsam. 



The most useful stains were gentian violet (Ohlmacher's 

 formula), iron-alum hieraatoxylin, thionin, Billet's modifica- 

 tion of the Giemsa stain, and Delafield's ha3matoxylin, while 

 dilute mcthylene-blue was best for intra vitam staining. Too 

 much reliance must not be placed on the various modifications 

 of the Homanowsky stain, for the structure of the membrane 

 is often only poorly revealed thereby. 



Movements of these Spirochcetes. 



Previous accounts of these phenomena are most meagre, 

 and yet descriptions of such movements would be of the utmost 

 importance. At this juncture it is necessary to state that 

 a typical Spirochete possesses an undulating membrane. 

 The type species of the genus, S. plicatilis, Ehrenberg, 

 recorded in 1833 from muddy water, was shown by Schaudinn 

 in 1905 to possess such a membrane. 



The movements of each of the two Spirochaetes in question 

 are most complex and difficult to resolve and interpret. A 

 Spirocluete moves very rajudly, especially S. anodontce — 

 indeed, so rapidly that it is almost iuipossible to analyze its 

 motion when travelling at full speed. Its path may be either 

 in a straight line or more or less in a circle. In the case of 

 slowly moving specimens it is seen that the organism moves 

 forward while turning on its long axis. The motion, then, 

 appears to be resolvable into at least two components — (i.) a 

 vibratory motion of flexion of the body, mainly for progres- 

 sion, and (ii.) a spiral or corkscrew movement of the body 

 as a whole, due to the winding of the membrane. The 

 corkscnnv motion is especially well seen in the case of 

 S. anodonttVy which has pointed ends. 



"Waves can be seen travelling down the thread-like body in 

 a direction opposite to that in which the organism is pro- 

 gressing. Many waves or sinuosities, some eight or ten, can 

 be seen along the body of rapidly moving forms, while only 

 some two to four may occur in more slowly moving ones. 

 The outline of the sinuosities is sometimes a little irregular — 

 that is, the contour is somewhat broken by much smaller 

 waves. 



The movements occur in jerks. The organism may 

 suddenly come to a dead stop or just as suddenly proceed 



