Their mode of division, too, is
thoroughly algoid. One finds, not unfrequently, groups of three and four
closely resembling _Protococcus_. Starch is invariably present; the wall
is true plant-cellulose, yielding a magnificent blue with iodine and
sulphuric acid, and the yellow coloring matter is identical with that
of diatoms, and yields the same greenish residue after treatment with
alcohol. So, too, in Velella, in sea-anemones, and in medusae; in all
cases the protoplasm and nucleus, the cellulose, starch, and chlorophyl,
can be made out in the most perfectly distinct way. The failure of
former observers with these reactions, in which I at first also shared,
has been simply due to neglect of the ordinary botanical precautions.
Such reactions will not succeed until the animal tissue has been treated
with alcohol and macerated for some hours in a weak solution of caustic
potash. Then, after neutralizing the alkali by means of dilute acetic
acid, and adding a weak solution of iodine, followed by strong sulphuric
acid, the presence of starch and cellulose can be successively
demonstrated. Thus, then, the chemical composition, as well as the
structure and mode of division of these yellow cells, are those of
unicellular algae, and I accordingly propose the generic name of
_Philozoon_, and distinguish four species, differing slightly in size,
color, mode of division, behavior with reagents, etc.
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