SPIROCHATA BALBIANII AND SPIROCHAHTA ANODONTH. 38 
Romanowsky stain. The principal fibrils do not easily stain 
deeply, nor do they “stand out” by this method of coloration. 
Gentian-violet and iron hematoxylin give better results. 
That these fibrils are strictly such and not merely folds is, I 
think, clearly proved by the occurrence, under certain condi- 
tions, of specimens described by Vlés (11), and the rupturing 
of the membrane in dying forms can actually be watched 
under the microscope. Further, the membrane in specimens 
of 8. balbianii from English oysters is rather too narrow 
to allow of much folding; far too narrow, I am sure, to 
allow of the appearance of some eight parallel myonemes by 
mere folding. Also Keysselitz (4) shows, in his figure 13a, 
the existence of myonemes in a “ macerated” specimen of 
Text-ric. 8.—This shows myoneme fibrils of the membrane 
“condensed” at the sides of the troughs formed by the membrane 
with the wavy outline of the body. ‘These are not due to folds. 
S.anodonte. I think it is quite likely that his specimen 
was not so much “ macerated” as that in dying the mem- 
brane of the parasite had relaxed. However, Keysselitz in 
his figure clearly shows the presence of myoneme threads, 
not “folds.” And again, the fibrils are condensed at the 
sides of the troughs, formed by the membrane and wavy 
body, where the membrane is seen passing over the side of 
the body (text-fig. 8). I do not understand myself how these 
“condensation ”’ appearances could be explained by the 
edges of folds. : 
In life, during active movements, the membrane is closely 
contracted round the body, and is not easily seen except as a 
halo around the organism. In faintly stained fixed prepara- 
tions, where the membrane has not properly taken up the 
stain, similar appearances occur. 
VOL. 52, PART 1.—NEW SERIES. 3 
