240 THE ESSEX NATURALIST.
a slight compression of the whole body. The anterior end was
rounded though apparently cleft into two by a shallow sulcus. The
single flagellum was about as long as the body, including the
processes and was normally held straight out, only the extreme
distal portion vibrating. Very little internal structure could be
seen. An irregularly rounded retractile body near the centre
was a usual feature and may have been the nucleus, but this was
not definitely determined. A number of small particles and.
globules commonly surrounded this central body and in some
instances a greater number of globules (paramylum?) nearly
filled the whole cell. The organism moved about very actively,
but not, so far as observed, as a free swimmer, for it always
glided in contact with some solid object. This gliding was
evidently brought about by the flagellum, the seemingly rigid
part of which was closely applied to the object over which the
organism was moving. This gliding type of movement is not
uncommon among certain flagellates, especially the Eugleninae,
but I do not think that it has ever been explained. It looks as
if the proximal part of the flagellum in these cases acts as if it
were a very elongated Amoeba of the Umax type flowing con-
tinuously forward and dragging the body of the organism after
it.
In addition to the foregoing there was also a peculiar form
of Flagellate (seen in seventeen samples) which deserves special
notice. From an early stage in this work certain little colourless
or slightly yellowish ovoid bodies were observed ranging from
16-30µ and consisting of a solid mass of more or less spherical
pellets or granules from 1µ to 2µ in diameter (figs. 6 and 7). In
the centre of the mass could usually be made out from one to
four or five cells of some sort from 7µ to 12µ, in which a con-
tractile vesicle could sometimes be seen. It was surmised that
these might be Flagellates, but it was not until much later that
specimens were found with the flagella extended and vibrating.
Each cell had only a single flagellum which came out from a more
or less pointed end of the cell, passing thence through the outer
layers of pellets. It seems probable that this is the same as the
organism described by Sandon as Phalansterium solilarium (8 and
9). But no "collar" could be seen, though as observation of the
cells could only be made through the mass of pellets, such a