Habits of Anthophysa Miilleri. 431 
Under a low magnifying-power this floccose matter appears 
to consist of clusters of very jagged, irregularly branching and 
contorted, semitransparent, intertwined stems, and projecting 
tapering and flexible twigs. Hach of the tips of the latter sus- 
tains a single more or less globose mass of spindle-shaped 
bodies, which radiate from a common centre of attachment, and 
are kept in a constant agitation by the spasmodic jerks of a 
long, stout, usually rigid, arcuate filament, with which the free 
end of each one is endowed. The whole bristling mass revolves 
alternately from right to left and from left to right, whirling 
upon its slender pivot with such a degree of freedom that one 
might almost suspect that it merely rested upon it and had no 
truer adhesion to it than the juggler’s top to the end of the 
bdton upon which it spins. The largest of these twirling groups 
contains as many as fifty fusiform bodies ; but most frequently 
not more than half that number are grouped together, and from 
this they vary in decreasing quantities down to “only one or two 
upon each filamentous twig. In the last instances the bodies 
are comparatively quiet, scarcely moving out of focus at each 
spasmodic twitch of the arcuate filament. On this account, and 
because they offer an unobstructed view, the latter are by far 
the most available as objects for the investigation of their internal 
organization. 
The relationship of the individual monads to the whole colony 
must, however, be studied where they are more numerously con- 
erevated, since, as will be shown presently, each monad sus- 
tains a definite relation to every other one, and to the twig to 
which it is attached. The larger colonies are frequently to be 
found swimming freely, with a rolling motion similar to that 
with which Volvox progresses. As a natural concomitant to this 
fact, twigs are to be met with here and there which do not bear 
anything at their tips. The colonies seem to break away very 
easily ; and on this account the specimens should not be lifted 
out of the water when transferring them to the watch-glass or 
whatever sort of observing-trough is used. 
Form, &e.—The adult monads have a truncate fusiform shape, 
and are slightly but quite appreciably flattened on two opposite 
sides, so that in an end view they appear to be broadly oval 
transversely. The attached end tapers gradually to a point; 
and on this account it is difficult to determine where the body 
ends and the twig begins. All of the members of a group radiate 
from a common point of attachment, to which they adhere by 
their tapering filamentous ends. The free end is truncate; but 
one corner of it, as if in continuation of the line along which 
the opposite flattened sides meet, projects in the form of a 
rather blunt triangular beak. At the inner edge of the base of 
30%* 
