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In the morphological characters of its elements this differs very conspicu-
ously from, species Є, for, whilst those of the latter are short, relatively thick,
and more or less of the type of the elements in, species ß, the elements here are
normally elongated, and present points of resemblance to those of species a,
or rather, perhaps, to those of species ÿ . As in the case of the previous species,
the precise form varies considerably in cultivations conducted under different
conditions. The description of the elements given above refers to those
present in common neutral or faintly alkaline gelatine or Agar-agar cultivations.
In non-neutralised Agar-agar they sometimes retain the same characters, and
at others more or less resemble those which they ordinarily present in neutra-
- l i s e d A g a r - a g a r c u l t i v a t i o n s w h i c h a r e d e r i v e d f r o m t h e g r o w t h o n p o t a t o e s . I n
these cases they normally appear in the form of straight rods, frequently of
very small size, and only in rare instances show any appreciable curvature. On
normal potatoes they have the form of small straight rods ; in cases where the
basis is abnormally acid and where the growth is comparatively slow and
otherwise departs from the normal standard, they sometimes are of considerable
size and decided curvature. They, like all the previously described species, are.
actively motile in fluids of suitable composition.
W hen grown in gelatine they snow a capacity for liquefying the medium;
somewhat inferior to that possessed by species E, and the channel which is
formed is normally of a distinctly different character, due to the fact that
liquefaction is very much more active at and towards the surface of the needle-
track than in its deeper parts. The result of this, in the earlier stages of culti-
- v a t i o n , i s t h e f o r m a t i o n o f a r e l a t i v e l y w i d e a n d s h a l l o w c r a t e r t e r m i n a t i n g
abruptly below in a narrow tube corresponding to the deeper part of the track.
When cultivated on common neutralised Agar-agar media rapid intersticial
and surface growth occurs. The latter ultimately forms a thick stratum, which,
as in the case of that of the previous species, is during the hot weather nor-
mally very adhesive and ropey (vide Table I). In non-neutralised Agar-agar
the growth is relatively rapid, but only occurs on the surface of the medium.
It resembles the previous species in being cultivable on potatoes, and in
becoming in certain cases so far acclimatised to them as a medium as to
permit of repeated transfers being successfully carried out. The growth, how-
ever, even in such cases, is never so free as in the case of similar cultivations
of species E,a n d d i f f e r s f r o m t h a t i n t h e l a t t e r i n o t h e r r e s p e c t s a l s o . I t a l s o
presents a pink color, but never one of the same strongly pronounced character
as in and it is generally of a distinctly yellowish tinge. It is never so thick,
and the consistence also is very different. In all the earlier cultivations it was
very soft and moist, but towards the beginning of the cold season, when vigor
- o u s g r o w t h c e a s e d t o o c c u r , t h e t e x t u r e b e c a m e e x t r e m e l y d e n s e a n d a l m o s t
cartilaginous, the color at the same time becoming, very pale and the, surface
coarsely wrinkled. For a long period it was easy to effect successful transfer of
the growth from potatoes to Agar-agar media, but the growth in the latter was
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