acid. Dr. Henry Carter is well
known as an old and experienced worker amongst amoeboid forms of
animal life, and, when in Bombay, he devoted himself to the
examination of the _Myxogastres_ in their early stage, and the result
of his examinations has been a firm conviction that there is no
relationship whatever between the _Myxogastres_ and the lower forms of
animal life. De Bary has himself very much modified, if not wholly
abandoned, the views once propounded by him on this subject. When
mature, and the dusty spores, mixed with threads, sometimes spiral,
are produced, the _Myxogastres_ are so evidently close allies of the
_Lycoperdons_, or Puffballs, as to leave no doubt of their affinities.
It is scarcely necessary to remark that the presence of zoospores is
no proof of animal nature, for not only do they occur in the white
rust (_Cystopus_), and in such moulds as _Peronospora_,[B] but are
common in algae, the vegetable nature of which has never been
disputed.

There is another equally important, but more complicated subject to
which we must allude in this connection. This is the probability of
minute fungi being developed without the intervention of germs, from
certain solutions. The observations of M. Trecul, in a paper laid
before the French Academy, have thus been summarized:--1. Yeast cells
may be formed in the must of beer without spores being previously
sown. 2. Cells of the same form as those of yeast, but with different
contents, arise spontaneously in simple solution of sugar, or to which
a little tartrate of ammonia has been added, and these cells are
capable of producing fermentation in certain liquids under favourable
conditions. 3. The cells thus formed produce _Penicillium_ like the
cells of yeast. 4. On the other hand, the spores of _Penicillium_ are
capable of being transformed into yeast.[C] The interpretation of this
is, that the mould _Penicillium_ may be produced from a sugar
solution by "spontaneous generation," and without spore or germ of any
kind. The theory is, that a molecular mass which is developed in
certain solutions or infusions, may, under the influence of different
circumstances, produce either animalcules or fungi. "In all these
cases, no kind of animalcule or fungus is ever seen to originate from
preexisting cells or larger bodies, but always from molecules."[D] The
molecules are said to form small masses, which soon melt together to
constitute a globular body, from which a process