384 Tet7'arliynchus ermaceus 
bulb. In such a section the fibres ai’e either cut obliquely so that short 
lengths of each are to be seen in the same field, or they may be cut so 
that comparatively long lengths are shown. As a rule the fibres lie quite 
loose from one another, especially when the proboscides are retracted, 
and the muscles of the bulbs are relaxed; but when the latter are 
contracted so as to produce the evagination of the proboscis quite a 
different appearance may be observed, and then an apparent cross- 
striation, but altogether too bold and striking an appearance to be a 
genuine one, may be seen. I have represented this appearance as seen 
under an oil immersion lens in PL XXIII, figs. 22 and 23. The former 
figure suggests that there are alternate light and dark fibres running 
parallel to each other and that while the darker fibres are not marked 
in any way the lighter ones are most distinctly crossed by transverse 
lines, each line indicating a constriction of the fibre. This appearance 
is as a rule most marked at the part of the wall of the bulb nearest to 
its internal surface (with respect to the axis of the scolex), and here the 
fibres may appear to be cut up into blocks. The latter figure represents 
a part of the muscular wall of the bulb near to the place of insertion 
of the fibres in the cuticularised external surface and here the fibres 
are obliquely striated so that they resemble closely twisted ropes of 
several strands. The diameter of these “ fibres ” is about 2-3 /r. 
I think it is quite evident that this so-called striation is really due to 
an interlacing of the fibres so that strands of two or more are formed. 
If this interlacing were very close the fibres might appear to cross one 
another at a right angle and so we should have an appearance of 
striation, but obviously a spurious striation. The proof of a real banding 
would be afforded by the staining of isolated fibres, and Pintner indeed 
figures such a dissociated fibre, but it appears to me to be likely that 
this structure was really compound. I have tried dissecting out the 
whole bulb and teasing it so as to break the muscular w’all and leave 
the ends of the fibres projecting. In such a preparation there is no 
trace of a real striation. 
The Excretory Canals. There are two longitudinal excretory canals 
in the more anterior proglottides on either side, but these vessels branch 
in the scolex and form a very complex system. The two main canals 
continue to run as far forward as the posterior extremities of the pro¬ 
boscis bulbs, but about this region they begin to branch so that four or 
five canals of approximately equal diameter may be seen lateral to the 
proboscis sheath.s. These main canals cannot be seen in the axial parts 
of the scolex, nor dorsal or ventral to the proboscis sheaths, behind the 
