H. B. Fantham 
407 
Fig. 22. Spirochaete which is very like those drawn in Figs. 19—21, but possesses 
rounded ends. (Delafield.) 
Fig. 23. Parasite with tapering ends and well-marked terminal basal granules. 
(Delafield.) 
Fig. 24. Parasite with rounded ends, showing clearly the edge of the coiled membrane. 
After treatment with Twort’s stain (neutral red and Lichtgrun) the edge of the 
membrane is stained red, with a delicate green film around it. 
Fig. 25. Spirochaete with clearly marked internal structure and approximately rounded 
ends. (Delafield.) 
Fig. 26. Spirochaete from the same preparation as that of Fig. 11, but slightly larger 
(older). Membrane relaxed, showing myonemes. (Delafield.) 
Fig. 27. Long Spirochaete with rounded ends, slightly longer than that shown in 
Fig. 24, and from the same preparation. (Twort’s stain.) 
Fig. 28. Long Spirochaete with rounded ends and chromatin arranged internally as dots 
or granules, not bars. (Delafield’s haematoxylin.) Similar forms are seen on 
preparations stained with Twort’s stain. 
Figs. 29—32. Typical Spirochaetes with undulatory outlines and membranes. These 
parasites were fairly broad. All from the same preparation. Lengths variable, and 
in some cases the ends were slightly tapering. (Delafield.) 
Fig. 33. Long Spirochaete with lower end slightly tapering. (Delafield.) 
Fig. 34. Shorter, broader parasite with rounded ends. Thionin. This Spirochaete from 
Tapes aureus is a typical short S. balbianii form, as seen in the oyster. 
Figs. 35—37. Somewhat broad forms from Tapes aureus. Their outlines are thrown into 
a few undulations of relatively great amplitude. The membrane of each is closely 
contracted round the body, but the edge of the membrane is, in each case, deeply 
staining. The ends are tapering to a variable degree, those of the same parasite 
often tapering unequally. These broad forms were found in the same preparation, 
stained with iron-haematoxylin. They were not very numerous, for there was a fair 
number of forms like those drawn in Figs. 19—21, and a large number of thin forms 
(cf. Figs. 1—5). Similar parasites seen in a preparation stained with gentian violet. 
Fig. 38, S. balbianii from an oyster obtained at Banyuls. The parasite is somewhat 
broad, and has distinctly rounded ends. Many of the Spirochaetes occurring in the 
same oyster were longer than the one drawn. (Delafield.) 
Figs. 39—44 illustrate longitudinal division. 
Fig. 39. Spirochaete whose membrane has divided at its lower end. The internal nuclear 
apparatus is arranged as a flattened spiral especially near the ends. Longitudinal 
division of the parasite similar to the one figured gives rise to forms like that drawn 
in Fig. 6. (Delafield.) 
Fig. 40. Spirochaete with double membrane and two sets of myonemes, resulting from 
division. (Delafield.) 
Fig. 41. Short thin form with membrane in process of longitudinal division. The 
parasite has already divided at the lower end. (Delafield.) 
Fig. 42. Longitudinal dividing form. The daughter parasites are separate for most of 
their length, but remain still unsplit at the upper end. (Delafield.) 
Fig. 43. Longitudinal division, the daughter forms having become free at their lower 
end. One of the daughter forms has its free end curled round. (Delafield.) 
Fig. 44. Nearly completed longitudinal division of a relatively thin Spirochaete into two 
thinner forms like those shown in Figs. 1—5. (Iron-haematoxylin.) 
Figs. 45—48. Bent or looped forms. In Fig. 46 the Spirochaete has bent in the middle 
and the two limbs intertwined. In Fig. 48 only one end has bent round. All stained 
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