SWIMMING AND CREEPING PROTOPLASTS. 29 
project from the surface of its body. In some instances the whole surface is thickly 
covered with short cilia, as in Vaucheria (fig. 71); in others the cilia form a close 
ring behind the conical or beak-like end of the pear-shaped body, as in Edogonium 
(fig. 77); and in others again, one or two pairs of long and infinitesimally thin 
threads, like the antenne of a butterfly, proceed from some spot, generally the 
narrow end (fig. 7° and 7%). Many forms are provided with a single long lash or 
flagellum at one extremity (fig. 7"), and yet others are spirally wound and are 
beset with cilia, thus presenting a bristly or hirsute appearance (fig. 7"). 
These ciliary processes have a combined lashing and rotatory motion, and by 
their means the protoplasts swim about in water. In many cases, however, swim- 
Fig. 7.—Swimming Protoplasm. 
1 Vaucheria ; 2? Qidogonium; 3 Draparnaldia; 4 Coleochete; 5and7 Botrydium; % Ulothrix; 8 Fucus; ® Funaria; 
; J y' ; ; 
10 Sphagnum; 1 Adiantum, 
ming is hardly an appropriate expression; certainly not if one associates the term 
with the idea of fishes swimming with fins. In point of fact there is, associated 
with progression in a particular direction, a continuous rotation of the protoplast 
round its longer axis, and on this account its motion may be compared to that of a 
rifle-bullet, since in both cases the movement of translation takes place in the 
direction of the axis round which the whole body spins. The movement in question 
is not unlike the boring of one body inside another; according to this, the soft 
protoplasts bore through the yielding water, and by this action make onward 
progress. 
The microscope magnifies not only the moving body, but also the path 
traversed; and when one contemplates a protoplast in motion, magnified, say, 
three hundred times, its speed appears to be three hundred times as fast as it 
really is. As a matter of fact, the motion of protoplasts is rather slow. The 
swarm-spores of Vaucheria, described above, which traverse a distance of 17 
millimeters in a minute are amongst the fastest. The majority accomplish an 
advance of not more than 5 m.m., and many only 1 m.m. per minute. 
