On the Study of Zoology | Page 9

nervous cords.
In the higher animals the phenomena which attend this transmission
have been investigated, and the exertion of the peculiar energy which
resides in the nerves has been found to be accompanied by a
disturbance of the electrical state of their molecules.
If we could exactly estimate the signification of this disturbance; if we
could obtain the value of a given exertion of nerve force by
determining the quantity of electricity, or of heat, of which it is the
equivalent; if we could ascertain upon what arrangement, or other
condition of the molecules of matter, the manifestation of the nervous
and muscular energies depends (and doubtless science will some day or
other ascertain these points), physiologists would have attained their
ultimate goal in this direction; they would have determined the relation
of the motive force of animals to the other forms of force found in
nature; and if the same process had been successfully performed for all
the operations which are carried on in, and by, the animal frame,
physiology would be perfect, and the facts of morphology and
distribution would be deducible from the laws which physiologists had
established, combined with those determining the condition of the
surrounding universe.
There is not a fragment of the organism of this humble animal whose
study would not lead us into regions of thought as large as those which
I have briefly opened up to you; but what I have been saying, I trust,
has not only enabled you to form a conception of the scope and purport
of zoology, but has given you an imperfect example of the manner in
which, in my opinion, that science, or indeed any physical science, may
be best taught. The great matter is, to make teaching real and practical,
by fixing the attention of the student on particular facts; but at the same

time it should be rendered broad and comprehensive, by constant
reference to the generalizations of which all particular facts are
illustrations. The lobster has served as a type of the whole animal
kingdom, and its anatomy and physiology have illustrated for us some
of the greatest truths of biology. The student who has once seen for
himself the facts which I have described, has had their relations
explained to him, and has clearly comprehended them, has, so far, a
knowledge of zoology, which is real and genuine, however limited it
may be, and which is worth more than all the mere reading knowledge
of the science he could ever acquire. His zoological information is, so
far, knowledge and not mere hear-say.
And if it were my business to fit you for the certificate in zoological
science granted by this department, I should pursue a course precisely
similar in principle to that which I have taken to-night. I should select a
fresh-water sponge, a fresh-water polype or a 'Cyanaea', a fresh-water
mussel, a lobster, a fowl, as types of the five primary divisions of the
animal kingdom. I should explain their structure very fully, and show
how each illustrated the great principles of zoology. Having gone very
carefully and fully over this ground, I should feel that you had a safe
foundation, and I should then take you in the same way, but less
minutely, over similarly selected illustrative types of the classes; and
then I should direct your attention to the special forms enumerated
under the head of types, in this syllabus, and to the other facts there
mentioned.
That would, speaking generally, be my plan. But I have undertaken to
explain to you the best mode of acquiring and communicating a
knowledge of zoology, and you may therefore fairly ask me for a more
detailed and precise account of the manner in which I should propose to
furnish you with the information I refer to.
My own impression is, that the best model for all kinds of training in
physical science is that afforded by the method of teaching anatomy, in
use in the medical schools. This method consists of three
elements--lectures, demonstrations, and examinations.
The object of lectures is, in the first place, to awaken the attention and
excite the enthusiasm of the student; and this, I am sure, may be
effected to a far greater extent by the oral discourse and by the personal
influence of a respected teacher than in any other way. Secondly,

lectures have the double use of guiding the student to the salient points
of a subject, and at the same time forcing him to attend to the whole of
it, and not merely to that part which takes his fancy. And lastly, lectures
afford the student the opportunity of seeking explanations of those
difficulties which will, and indeed ought to, arise in the course of his
studies.
But for a student to derive the utmost