394 
Spirochaetes of Tapes aureus 
endeavour to study myonemes. The results obtained after treatment 
of the parasites with gold-chloride or with methyl alcohol were not 
superior to those obtained after using somewhat less elaborate methods. 
Observations on the Living Spirochaetes of Tapes aureus. 
The Spirochaetes of Tapes aureus were examined alive in a medium 
consisting of crystalline style substance to which a little filtered sea¬ 
water had been added. Their movements were very active, and similar 
to those of S. balbianii and S. anodontae, in that they may be resolved 
“ into at least two components: (i) an undulatory flexion of the body, 
mainly for progression, and (ii) a spiral or corkscrerv movement of the 
body as a whole, due to the winding of the membrane.” (Fantham, 
I. 1908, p. 17; compare also vi. 1907, p. 495.) 
While examining the rapidly moving living specimens, it was 
evident that considerable variation existed among the Spirochaetes 
from the style of any given Tapes aureus, and that detailed examination 
of stained preparations would he necessary to determine whether more 
than one species of Spirochaete was present, or only a number of 
varieties of the same species. 
Both longitudinal and transverse division were seen to occur in the 
living Spirochaetes. In longitudinal division the daughter individuals 
were observed to diverge gradually, like the legs of a compass, while 
still remaining undivided at one end. In transverse division the parent 
form usually elongated slightly and divided about a central node. 
Waves travelled in opposite directions from the ends of the organism 
about to divide towards its middle, and then back again. A series of such 
waves ensued, and finally the parent organism parted in the middle. 
The process of transverse division in living Spirochaetes has been 
described by Miss Porter and myself (1909) for S. anodontae, S. recur- 
rentis and S. duttoni. 
Sometimes Spirochaetes of Tapes were seen to bend over and loop 
in the middle (cf. PI. VI, Figs. 45—48) forming a U, the halves of 
which sometimes intertwined. These looping forms are perhaps 
suggestive of division, but in no case was division seen to occur. 
Usually the Spirochaetes untwined and swam away. Similar phenomena 
have been described and figured for S. balbianii and S. anodontae by 
Miss Porter (1.909). 
A few Spirochaetes were seen to coil themselves spirally, either at 
one end or in the middle. Later the Spirochaetes uncoiled and swam 
