Scientific American Supplement, No. 643 | Page 7

allusion again to the field of inquiry in which I
have spent so many happy hours. It is, as you know, a region of life in
which we touch, as it were, the very margin of living things. If nature
were capricious anywhere, we might expect to find her so here. If her
methods were in a slovenly or only half determined condition, we
might expect to find it here. But it is not so. Know accurately what you
are doing, use the precautions absolutely essential, and through years of
the closest observation it will be seen that the vegetative and vital

processes generally, of the very simplest and lowliest life forms, are as
much directed and controlled by immutable laws as the most complex
and elevated.
The life cycles, accurately known, of monads repeat themselves as
accurately as those of rotifers or planarians.
And of course, on the very surface of the matter, the question presents
itself to the biologist why it should not be so. The irrefragable
philosophy of modern biology is that the most complex forms of living
creatures have derived their splendid complexity and adaptations from
the slow and majestically progressive variation and survival from the
simpler and the simplest forms. If, then, the simplest forms of the
present and the past were not governed by accurate and unchanging
laws of life, how did the rigid certainties that manifestly and admittedly
govern the more complex and the most complex come into play?
If our modern philosophy of biology be, as we know it is, true, then it
must be very strong evidence indeed that would lead us to conclude
that the laws seen to be universal break down and cease accurately to
operate where the objects become microscopic, and our knowledge of
them is by no means full, exhaustive, and clear.
Moreover, looked at in the abstract, it is a little difficult to conceive
why there should be more uncertainty about the life processes of a
group of lowly living things than there should be about the behavior, in
reaction, of a given group of molecules.
The triumph of modern knowledge is the certainty, which nothing can
shake, that nature's laws are immutable. The stability of her processes,
the precision of her action, and the universality of her laws, is the basis
of all science, to which biology forms no exception. Once establish, by
clear and unmistakable demonstration, the life history of an organism,
and truly some change must have come over nature as a whole, if that
life history be not the same to-morrow as to-day; and the same to one
observer, in the same conditions, as to another.
No amount of paradox would induce us to believe that the combining

proportions of hydrogen and oxygen had altered, in a specified
experimenter's hands, in synthetically producing water.
We believe that the melting point of platinum and the freezing point of
mercury are the same as they were a hundred years ago, and as they
will be a hundred years hence.
Now, carefully remember that so far as we can see at all, it must be so
with life. Life inheres in protoplasm; but just as you cannot get
_abstract matter_--that is, matter with no properties or modes of
motion--so you cannot get abstract protoplasm. Every piece of living
protoplasm we see has a history; it is the inheritor of countless millions
of years. Its properties have been determined by its history. It is the
protoplasm of some definite form of life which has inherited its specific
history. It can be no more false to that inheritance than an atom of
oxygen can be false to its properties.
All this, of course, within the lines of the great secular processes of the
Darwinian laws; which, by the way, could not operate at all if caprice
formed any part of the activities of nature.
But let me give a practical instance of how what appears like fact may
override philosophy, if an incident, or even a group of incidents, per se
are to control our judgment.
Eighteen years ago I was paying much attention to vorticellæ. I was
observing with some pertinacity _Vorticella convallaria_; for one of the
calices in a group under observation was in a strange and semi-encysted
state, while the remainder were in full normal activity.
I watched with great interest and care, and have in my folio still the
drawings made at the time. The stalk carrying this individual calyx fell
upon the branch of vegetable matter to which the vorticellan was
attached, and the calyx became perfectly globular; and at length there
emerged from it a small form with which, in this condition, I was quite
unfamiliar; it was small, tortoise-like in form, and crept over the branch
on setæ or hair-like pedicels; but,