50 Infusoria: What are they ?
the student of Infusoria is undoubtedly furnished hy weed-
grown ponds. From these he may always expect to reap an
abundant harvest. Fragments of the weeds, more particularly
the finely divided varieties, such as Myriophyllum, Ranunculus,
and the rootlets of Duckweed (Lemna), should be placed in a
bottle and examined carefully for colony-stocks of the
"Trumpet" and "Bell" animalcules, which may be easily
detected with the assistance of a pocket lens, and may even
be recognised as flocculent growths upon these plants with
the unaided vision. Many of the free Ciliata, when abun-
dantly developed, will also be rendered visible as glistening
specks progressing through the water with that peculiar
locomotive action distinctive of its kind. Excepting in the
case of the social Euglena, and a few other types, whose
presence, as already mentioned, lends a distinct coloration to
the water, the collection of the Flagellata is pre-eminently an
act of faith, and not of sight. Notwithstanding that the
weeds gathered may appear to the unassisted eye, or even as
examined with the pocket lens, completely barren, they may
on submission to the higher powers of the microscope be
found to be teeming with flagelliferous types. The collector,
moreover, should be advised not to immediately throw away
what appears on a preliminary investigation to be an unpro-
ductive gathering. Such gatherings often contain an abun-
dance of latent germs, which after an interval of a few days
develop luxuriantly on the surface of the plants, or on the
sides of the receptacle that contains them. Two of the first
and most remarkable flagellate types yet met with, Rhipido-
dendron Huxleyi and Spongomonas sacculus, as delineated in
the exhibited plates ('Manual of the Infusoria,' pl. xvi., figs.
4-9, and pl. xii., figs. 17-23), were thus obtained fortuitously
by myself from bog water collected on Dartmoor, and which,
as gathered and submitted to preliminary examination, be-
trayed no trace of abnormal infusorial life. Within a few
days, however, little rust-red patches made their appearance
upon the sides of the bottle, and developed within a brief
interval into the colony-stocks, represented in the plates
submitted; these were not only distinctly visible to the