

LIFE-HISTORIES AND THEIR LESSONS, I71 

may even be deformity, but this is exception, and may, in the 
course of time, be reduced to a law. But always there is varia- 
tion, and if that variation be for the benefit of the organism, it will 
survive and be perpetuated. But there are no leaps—there is no 
caprice. The egg of a linnet will not produce a grasshopper, or 
that of a trout a butterfly. And if there were not equal certainty 
that the cells begotten by the egg were equally true to their mission, 
and loyal to each other, as the egg-cell was true to its work, could 
organic life exist at all? It seems impossible. 
But there are certain phoenomena in the protoplasm of cells 
which, if not understood, may lead to the profoundest error. This 
especially amongst the lowlier forms of life. 
Protoplasm is soft and plastic, varying in consistence, but it is 
never a fluid proper. It defies the laws of fluids; and one of the 
things common to it in the lowlier forms of plant-life especially, is 
circulation or cyclosis within the cell. 
To illustrate this we may take an illustration placed at our dis- 
posal, viz., the stellate hair from a bud of Althea rosea. In this 
minute vegetable growth the circulation of the protoplasm is clear 
and beautiful. The course of the stream being clearly visible. 
Now, suddenly rupture these cells, the protoplasm is at once set at 
liberty, but is not dead; and, consequently, it creeps about like a 
living amceba for minutes, or possibly for hours. 
The wonderful movements of the naked protoplasmic bodies of 
Myxomycetes are known to every careful botanist. 
But put some Vaucheria into a live-box, and let it slowly, as it 
must do, decompose and die. The plasmodia does its dying 
slowly; but the sacs are ruptured by decomposition—and what 
happens? Here (Plate I., Fig. r) is an illustration directly from 
life in two cases. At @ the protoplasm has emerged from the 
cell, carrying a clear globule with it, and then, after a few moments 
of amoeboid movement, became a walled cell and granules, as may 
be seen at J. 
In the other instance, shown by c, the protoplasmic contents 
broke off from the cell, and became free, like an amceba. In its 
free state it is shown at d@. This drawing is a facsimile of it as it 
appeared at an interval of four minutes. The outline shows, in 
fact, its shape four minutes before. And this movement continued 
for two and a half hours, and then both pieces of plasma died and 
dissolved. 
What was this? a change in the mission of the vaucheria proto- 
plasm? No; only the pertinacity of the life that was in it, with its 
necessary properties. E ; 
And let it be observed this is by no means a rare incident. It is 
one of the common facts of botanical physiology. 
I shall serve the end I have in view, then, if I ask you now to 
