ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
669 
In spite of tlie splendid result attained by it, as biologists we gain 
nothing. We are where we were, and studies of cells and cell life must be 
made with dry and immersion apochromatics of N.A. 1 *4, or at most 1 * 5. 
With this fact before us, it will be well for us to remember what we 
are searching for as experts, in tracking the life and behaviour of various 
cells, and founding, or endeavouring to found, a comparative morphology 
and physiology of cells and unicellular bodies. 
Tlio sphere of all research is strictly physical. Existence, not the 
cause of existence, succession, not the cause of succession, is our object. 
There can be, perhaps, but little doubt that life is a cause of phenomena, 
not a phenomenon in itself. As such it is impalpable to the scientific 
method. It cannot be the subject of experiment nor the object of a 
demonstration. 
Certainly, in tracking the essential activities of life home to the 
individual cell amidst its class, or group of cells, or to the unicellular 
organism, we are coming into closer quarters with the mysterious cause 
of the phenomena of vitality. But its nature eludes us as much as 
before. We are, of course, no nearer to the solution of the problem of 
what life — the cause of all the phenomena of living things — is, than we 
were before. 
We track its phenomena to almost their last scene of phenomenal 
action, but it is still only phenomena we are studying. 
I do not assume that life is not a physical cause. We have no justi- 
fication for doing so. But if we would go further back than the finally 
accessible phenomena of cell morphology and cell function it would 
appear that we must penetrate the mystery of atomic properties as they 
are found in living things, for it is, so far as our present knowledge 
can carry us, to the unaccountable combination of thoroughly known 
chemical elements that life and its properties are due. The at present 
unanswerable question is how not-living substances, such as 0, H, 0, N, 
with whose properties we are so familiar, should so combine, as in their 
combination to acquire the properties of life. 
But while our inquiry will strictly confine us to phenomena, the 
study of the phenomena of minute cellular structure and minute uni- 
cellular organisms is essentially the highest, and, in some senses, the 
newest line of inquiry open to patient and enlightened study. 
Its promise is enormous. But I would urge the necessity for the 
study of the living cell ; the dead cell, dried and stained, is a poor 
representative of the living cell both in form and internal appearance. 
The unicellular organisms, as the simplest types of cell, deserve the 
closest and most untiring research before broad inferences are made upon 
the nature and behaviour of grouped cells in tissues. 
As there can be no abstract protoplasm — no protoplasm not belonging 
to a specific organism — and not therefore presenting itself to us as 
protoplasm with its own specific history and inherited qualities, so there 
cannot be an abstract cell. That can only exist in the imagination of 
the theorist. Every cell we meet with in biological realities is not only 
a cell, but a cell complicated with its own peculiar history and inheritance, 
and therefore those cells with the least complicated history should 
command our earliest and most thorough study ; and from these we may 
safely advance to the more and the most complex. 
