as Infusoria flagellata. 257 
which, although it has a pretty strong resemblance to Huglena, 
heightened by the presence of a red eye-spot (s), will be found 
upon investigation to possess some additional and decidedly 
different characters. In the first place, it has two vibrating 
lashes (ff, #?), which differ remarkably among themselves both 
in position and character. One of them is always carried in 
front, like a sort of proboscis (#1); and in fact it seems to have 
the office of such an organ, like that of an elephant, to feel and 
to take hold of objects. J must confess that I was struck with 
astonishment at the apparent intelligence with which the in- 
fusorian extended, and twisted, and turned, and felt about with 
this extraordinary organ. Never did an elephant seem to use 
his trunk with more thoughtfulness. With like control did 
the animal also use the other lash (ff%), always keeping it 
turned back along the body, so that it formed a kind of move- 
able keel when the little creature glided along in its watery 
element, or was used to sway it from side to side, or oftentimes 
to raise it up on its tail by forming a prop, as we see it in this 
other figure (fig. 73). 
_ © The motory or propelling power, on the other hand, is re- 
stricted, at least in the greatest measure, to another: kind of 
yibratile cilia, These are very short, and are crowded toge- 
ther in great numbers (c/) in a broad furrow or depression (/) 
which extends over half the length of the body, along its in- 
ferior middle line, When the body is turned over, and the 
anterior end retracted and swelled out sideways, the furrow 
(fig. 73, f) becomes quite conspicuous, and the extent of the 
group of minor cilia (c/) is easily ascertained, ‘They are very 
minute, and in constant motion, propelling the body backward 
and forward, up and down, to the right or left, according as it 
is steered by the trailing lash (7?) which extends along its 
length. Thus it is that, although similar in form, a diversity 
of functions is laid upon these three kinds of cilia that amounts 
to the most marked specialization, through the simplest means 
—in fact so simple that the eye cannot detect them in any 
form besides that of proportion and position, and certainly not 
in the intimate structure of these bodies. The whole body, 
too, possesses a flexibility and extensibility scarcely inferior to 
its cilia: at one moment it is darting through the water, sha 
as a lance at both ends; and at the next it is as round as a ball, 
or worming its way through tortuous passages with every 
ossible degree of flexure short of actually tying itself into a 
not.’ 
It would be difficult to say now whether Heteromastix be- 
longs to the Flagellata rather than to the Ciliata, or vice versa. 
The structure, position, and peculiar mode of action of its fla~ 
