a 
Sept. 18, 1873] 
NATURE 
421 
Similitude, not indentity, is the effect of natural agencies in the 
continuation of life-forms, the small differences from identity 
being due to limited physical conditions, in harmony with the 
general law that organic structures are adapted to the exigencies 
of being. Moreover, the structures are adaptable to new con- 
ditions ; if the conditions change, the structure changes also, but 
_ not suddenly ; the plant or animal may survive in presence of 
slowly altered circumstances, but must perish under critical 
inversions. These adaptations, so necessary to the preservation 
_ of a race, are they restricted within narrow limits? or is it possi- 
_ ble that in course of long-enduring time, step by step and grain 
by grain, one form of life can be changed and has been changed 
to another, and adapted to fulfil quite different functions? It is 
thus that the innumerable forms of plants and animals have been 
AC aa ai ” in the course of ages upon ages from a few original 
pes 
This question of development might be safely left to the 
prudent researches of Physiology and Anatomy, were it not the 
case that Palzeontology furnishes a vast range of evidence on the 
real succession in time of organic structures, which on the whole 
indicate more and more variety and adaptation, and in certain 
ts a growing advance in the energies of life. Thus at first 
only invertebrate animals appear in the catalogues of the inhabi- 
tants of the sea, then fishes are added, and reptiles and the 
higher vertebrata succeed ; man comes at last, to contemplate 
_ and in some degree to govern the whole. 
The various hypothetical threads by which many good natura- 
lists hope to unite the countless facts of biological change into 
an harmonious system have culminated in Darwinism, which 
_ takes for its basis the facts already stated, and proposes to explain 
the analogies of organic structure by reference to a common 
origin, and their differences to small, mostly congenital, modifica- 
tions which are integrated in particular directions by external 
ag conditions, involving a “struggle for existence.” Geo- 
ogy is interested ‘in the question of development, and in the 
particular exposition of it by the great naturalist whose name it 
bears, because it alone possesses the history of the development 
in time, and it is to inconceivably long periods of time, and to 
the accumulated effect of small but almost infinitely numerous 
changes in certain directions, that the full effect of the transfor- 
mations is attributed. 
For us, therefore, at present it is to collect with fidelity the 
evidence which our researches must certainly yield, to trace the 
relation of forms to time generally and physical conditions locally, 
to determine the life-periods of species, genera, and families in 
different regions, to consider the cases of temporary interruption 
and occasional recurrence of races, and how far by uniting the 
results obtained in different regions the alleged * imperfection of 
the geological record” can be remedied. 
The share which the British Association has taken in this 
great work of actually reconstructing the broken forms of ancient 
life, of repeopling the old land and older sea, of mentally re- 
viving, one may almost say, the long-forgotten past, is considerable, 
and might with advantage be increased. We ask, and wisely, 
from time to time, for the combined labour of naturalists and 
geologists in the preparation of reports on particular classes or 
families of fossil plants and animals, their true structure and 
affinities, and their distribution in geological time and geogra- 
phical space. Some examples of this useful work will, I hope, 
be presented to this meeting. Thus have we obtained the aid 
of Agassiz and Owen, and have welcomed the labours of Forbes 
and Morris, and Lycett, and Huxley, of Dawkins and Egerton, 
of Davidson, Duncan, and Wright, of Williamson and Carruthers 
and Woodward, and many other eminent persons, whose valuable 
results have for the most part appeared in other volumes than 
our own, 
Among these volumes let me in a special manner recall to 
your attention the priceless gift to Geology which is annually 
offered by the Paleontographical Society, a gift which might 
become even richer than it is, if the literary and scientific part of 
our community were fortunate enough to know what a perpetual 
treasure they might possess in return for a small annual tribute. 
The excellent example set and the good work recorded in the 
Memoirs of the Society referred to have not been without influence 
on foreign men of science. We shall soon have such Memoirs 
from France and Italy, Switzerland and Germany, America and 
Australia ; and I trust the effect of such generous rivalry will be 
to maintain and increase the spirit of learned research and of 
original observation which it is our privilege and our duty to 
foster, to stimulate, and to combine. 
On all the matters, indeed, which have now been brought, to 
your thoughts the one duty of geologists is to collect more and 
more accurate information ; the one fault to be avoided is the 
supposition that our work in any department is complete. We 
should speak modestly of what has been done; for we have 
completed nothing, except the extinction of a crowd of errors, 
and the discovery of right methods of proceeding toward the 
acquisition of truth. We may speak hopefully of what is to be 
accomplished ; for the right road is before us. We have taken 
some steps along it; others will go beyond us and stand on 
higher levels. But it will be long before anyone can reach the 
_ height from which he may be able to survey the whole field of 
research and collect the results of ages of labour. 
SECTION D.—BroLocy 
OPENING ADDRESS BY THE PRESIDENT, PROF, ALLMAN 
The present Aspects of Biology and the Method of Biological 
Study 
For some years it has been the practice at the meetings of 
this Association for the special presidents to open the work 
of their respective sections with an address which is supposed to 
differ, in the greater generality of its subject, from the ordinary 
communications to the sections. Finding that during the present 
meeting this duty would devolve on myself, I thought over the 
available topics, and concluded that a few words on the present 
aspect of Biology and the method of Biological Study would 
best satisfy the conditions imposed. 
I shall endeavour to be as little technical as my subject will 
allow, and though I know that there are here present many to 
whom I cannot expect to convey any truths with which they are 
not already familiar, yet in an address of this kind the speaker 
has no right to take for granted any large amount of scientific 
knowledge in his audience. Indeed, one of the chief advan- 
tages which result from these meetings of the British Association 
consists in the stimulus they give to inquiry—in the opportunity 
they afford to many of becoming acquainted for the first time 
with the established truths of Science, and the initiation among 
them of new lines of thought. 
And this is undoubtedly no smali gain; for how many are 
there who, though they may have reaped all the advantages 
which our established educational systems can bestow, are yet 
sadly deficient in a knowledge of the world of life which sur- 
rounds them. It is a fair and wonderful world, this on which 
we have our dwelling-place, and yet how many wander over it 
unheedingly ? by how many have its lessons of wisdom never 
been read ? how many have never spared a thought on the beauty 
of its forms, the harmony of its relations, the deep meaning of 
its laws ? 
And with all this there is assuredly implanted in man an un- 
dying love of such knowledge. From his unshaken faith in 
causation he yearns to deduce the unknown from the known, to 
look beyond what is at hand and obvious to what is remote and 
unseen. 
conception of Biology and Function of the Scientific Method 
Under the head of Biology are included all those departments 
of scientific research which have as their object the investigation 
of the living beings—the plants and the animals—which tenant 
the surface of our earth, or have tenanted it in past time. 
It admits of being divided under two grand heads : Morpho- 
logy, which treats of Form, and Physiology, which treats of 
Function ; and besides these there are certain departments of 
Biological study to which both Morphology and Physiology con- 
tribute, such as Classification, Distribution, and that department 
of research which is concerned with the origin and causes of 
living and extinct forms. ; : 
By the aid of observation and experiment we obtain the ele- 
ments which are to be combined and developed into a science of 
living beings, and it is the function of the scientific method to 
indicate the mode in which the combinations are to be effected, 
and the path which the development must pursue. Without it 
the results gained would be but a confused assemblage of iso- 
lated fects and disconnected phenomena ; but aided by a philo- 
sophic method, the observed facts become scientific propositions, 
what was apparently insignificant becomes full of meaniy, and we 
get glimpses of the consummate laws which govern the whole. 
