﻿448 ASHBURN AND CRAIG. 



glancing light bnt no more, to a very sluggish motion which so closely 

 simulates entire passivity as to leave the observer in serious doubt as to 

 whether any is present, other than that clue to currents in the serum. 



When motion has ceased to a sufficient degree to permit of the organ- 

 ism being well seen and clearly identified, it is always slow. It consists 

 of a slight rotation on the axis of the spiral representing the appearance 

 of a corkscrew movement, and a mild and gentle waving and bending of 

 the entire organism. These two varieties of motion combined, cause the 

 treponema to pass across the field, to rise and sink, necessitating much 

 change of focus, or, if one end of the organism it attached to the cover 

 glass, or to foreign matter in the field, as is frequently the case, to lash 

 or to swing in an indolent manner from this fixed point. 



This motion and what we consider the common form of the organism 

 may best be observed in capillary tube preparations about one day old. 

 In that length of time the accompanying bacteria have usually not multi- 

 plied so greatly as to occupy the large part of the field they do later, 

 while the treponema have ceased to move actively, and have usually 

 increased in number and are readily found. In these preparations, or 

 stained ones made from them, what are most commonly called the 

 dividing forms are more frequently seen. 



DIVIDING FORMS. 



For ease of description we may designate these forms as additional 

 types I, K, L and M. 



Type I is fairly common and, as indicated by Plate IV shows some 

 variety in the arrangement of its component parts. Essentially it con- 

 sists of two or more spirals which are attached one to another by their 

 ends. In some, this attachment is such as to be almost or quite indistin- 

 guishable from type B. 



Type K is also quite common and differs from I in that the attachment 

 is firmer and involves a greater part of the length of the parasite. It 

 is as though the wire of the spiral had been split throughout a quarter, 

 a half, or three quarters of its length, the turns being preserved. How- 

 ever, the two sections of the spiral are frequently unequal in length. The 

 appearance presented in such cases has been figured by Siedlecki and 

 Krystalowicz(23) as representing conjugation. 



Type L is probably the most striking and pretty form to be seen. 

 Here the two component parts are intertwined throughout their length, 

 the two ends at one extremity, however, being free. Occasionally all 

 four ends are free, but more commonly those at one extremity are fused, 

 or they take their origin from a common dot or knob. ■ 



These types, I, K, and L, have usually been considered indicative of 

 longitudinal division, and they so appear to us. 



