276 
Division in Spirochaetes 
were in this case approximately equal, and the movement, though 
rather spasmodic, was more rapid than in (1). 
II. Tt 'ansverse Division. I was struck by the fact that in most 
spirochaetes that had attained considerable length—9 to 14 curves— 
there appeared a weak point, about half-way along the organism, at 
which bending occurred, as the arm bends at the elbow-joint. In some 
cases there seemed to be a distinct constriction at this point. 
On eleven occasions I saw what I should interpret as transverse 
division. 
1. An individual with a thin drawn-out portion in the middle was 
seen to separate into two at that point. 
Fig. 1. Fig. 2. 
2. Two short spirochaetes joined only by a fine protoplasmic 
bridge were watched for some time, during which the connection 
thinned out till they separated. This appearance has been aptly 
likened by Schilling to the drawing out of a glass tube in a flame. 
3. A long individual, with approximately 14 curves, showed a thin 
zone half-way along its length. It was watched for 20 minutes. During 
this time the thin portion became more and more drawn out and the 
two halves separated, after spasmodic and “purposeful” wrenching 
movements. 
4. Two short individuals—one rather longer than the other— 
connected by a fine strand, separated after having been watched for 
several minutes. 
5. A long individual (about 12—14 curves), with a thinner median 
portion was watched for 20 minutes. Its movements were agitated and 
