March 11,1871.] 
THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. 
721 
THE MICROSCOPE AND ITS 
REVELATIONS.* 
BY W. B. CARPENTER, M.D., F.R.S., F.G.S., F.L.S. 
When I last had the pleasure of addressing you, 
I directed your attention to some of those lowest and 
simplest forms of Animal life which have of late 
years been very much the subject of observation 
amongst Naturalists, and the study of which has 
added, I tliink I may say, a great deal to the science 
of General Physiology, because it has led us to per¬ 
ceive that some of the most important functions of 
life in the higher animals are really performed by 
the protoplasmic substance which enters very largely 
into the composition of their bodies, and which, as it 
were, prepares the material that is turned to higher 
account in the more complicated structure of those 
organisms that we are accustomed to call superior. 
Let me dwell for a moment on what we mean by 
superior and inferior organisms. By superior we 
mean those in which there is the greatest division of 
labour, in which the work is most highly specialized, 
in which there is a particular apparatus for each 
function, and hi which that apparatus is carried to 
its highest degree of perfection. Why do we call 
the hand a superior instrument to the corresponding 
extremity of any of the lower animals, even the 
most highly organized apes? Because it is much 
more highly specialized. We do not use it for sup¬ 
port or progression; it is entirely used with us for 
prehension, for laying hold of things. We can op¬ 
pose the thumb to every individual finger, but an 
ape cannot; he can only take hold with his whole 
hand, and he uses his anterior as well as his poste¬ 
rior extremities for support and progression. That 
is one instance of what we mean by specialization. 
I showed you on the last occasion that a simple par¬ 
ticle of annual jelly lays hold of food by drawing it 
in to itself without a mouth, and extemporizes, so to 
speak, a stomach; that without any proper mouth, 
and without any proper stomach, it performs the 
function of digestion ; that the material imbedded in 
it is dissolved by its means, and converted into the 
same protoplasm; that it has also in itself the 
power of motion; and again, that if it has any power 
of feeling, this must be diffused throughout the same 
protoplasm. But this protoplasm in us is simply 
the preparative material for all that wonderful me¬ 
chanism which, with us, as in all higher animals, is 
made subservient to those much more highly spe¬ 
cialized and complicated functions which man is 
capable of performing, and which all minister in the 
end to the maintenance of his conscious life, his in¬ 
tellectual power, his moral feeling and so on. 
This evening it is my purpose to carry you into 
a slightly different field—into that domain of life in 
which we have active motion, and in which we have 
again the curious phenomena of motion in plants;— 
to carry you, in fact, into the domain which has been 
the field of great perplexity to naturalists, but which 
is gradually becoming, by the careful study which has 
been bestowed upon it, more and better understood. 
"When I began to devote myself to the application 
of the microscope to the study of the lower forms of 
plants and animals, it was believed, with very few 
exceptions, that everything which has motion must 
be an Animal. An old observer, Vaucher, of Geneva, 
* Lecture delivered at the Evening Meeting of the Phar¬ 
maceutical Society of Great Britain, March 1, 1871. See 
ante, p. 641. 
Third Series, No. 37. 
had directed attention to the fact that little particles 
issue from some of those green threads that you see 
in running streams, the Conferva, which particles, he 
said, were animals in a very early stage of existence, 
and that they then returned again to the form of 
plants. He said they were animals, because they 
had the power of motion. He watched them very 
carefully with the imperfect instrument he had, and 
he found that the motion gradually subsided; they 
settled down, and then began to develope into un¬ 
doubted plants. Here is a diagram of one of the 
plants which Vaucher observed; it is known as 
Vaucheria clavata ,—the club-shaped Vaucheria ,— 
from the tendency of its ends to swell into these 
club-shaped masses. It is just one of those green, 
thread-like plants that you will see in running 
streams, very often attached, for instance, to the 
stones where water is running over a mill-dam. 
When it is in its ordinary growing condition it is 
simply a filament; but when it is going to put forth 
one of those curious buds, so to speak, it swells into 
a knob, and there is an accumulation of green mat¬ 
ter in the extremity. This separates itself from the 
green matter in the tube, and by-and-by it is seen 
that this green knob has a distinct envelope of a 
greater thickness than the proper wall of the tube. 
Then the covering bursts, and from the interior of the 
tube there issues forth this body, which is known 
by the name of the zoospore. The term spore is 
given to the reproductive particles of the lower 
plants as distinguished from the seeds of the 
higher. The seeds, you know, contain with the 
germ or embryo a store of nourishment, laid up 
either in the cotyledons when fleshy, as in the pea 
or bean, or in the albumen when the seed is albumi¬ 
nous, as in wheat and many other plants. In either 
case that store is applied to the nutrition of the em¬ 
bryo before it is sufficiently developed to obtain its 
own nourishment, to get its own bread, as it were. 
Now, hi the cryptogamic tribes generally we find 
that these minute particles are launched forth upon 
the world with a power of getting their own bread 
at a much earlier period, and therefore there is not 
in them the same store of nourishment that is sup¬ 
plied to the higher plants. The word spore is ap¬ 
plied to tilings really very different, of which I shall 
give you an illustration by-and-by. You are not 
to suppose that the spore always represents the seed 
of the higher plants. In this case the spore is a 
sort of little bud, and it is called a zoospore, from 
the fact of its having a power of motion very much 
like animal motion ,—zoon meaning animal, and 
zoospore, a spore endowed with power of motion 
lik e an animal. This little bud, with a rather thick 
casing, issues forth from the end of the tube, which 
bursts and gives it out. Then it takes a spheri¬ 
cal form, and then, after a little time, it is seen to 
be in active motion, and this active motion is given 
to it by the vibration of a fringe of minute liair-like 
processes, which are termed cilia. These are the 
active agents of movement in the lower plants, in 
the lower animals, and in various parts of our own 
bodies. (For instance, the whole surface of the re¬ 
spiratory tract, as it is called, all the mucous mem¬ 
brane of the air-passages down to the air-cells of the 
lungs, is covered with these cilia.) By the action of 
these cilia forming this fringe, this little particle is 
carried about in the w r ater, and thus the large num¬ 
ber that issue from the various filaments of the plant 
are dispersed, and carried to new localities. Alter a 
