96 
The President's Address. 
by the microscopical observer that the question of the spon- 
taneous generation of animals and plants can be set at rest. 
As far as the results of present investigation go^ there seems 
to be no satisfactory evidence that the organisms which we 
call plants and animals have had any other origin than or- 
ganisms endowed with vital properties similar to themselves; 
but as to how far any one of these organisms may differ from 
its predecessors through all time, we are in the dark. At 
first sights it looks as if this question of the origin of species 
was one that must be for ever veiled from our sight ; and if 
it had not been raised by an inquirer so competent to judge 
of the possibilities of our science^ we might have passed by 
the challenge unheeded. But we have been invited to ascer- 
tain the amount of change of which each individual organism 
is capable, and especially to observe how far such changes 
impress themselves permanently on the organisms, or series 
of organisms, in which it takes place. If by the collation 
of past well-observed facts with those which present them- 
selves before us at the present day, and allowing the largest 
amount of time that can be reasonably demanded_, we come 
to the conclusion that the higher organisms could be degraded 
to the forms of the microscopic Protophyta or Protozoa, or 
that these latter could be elevated to the condition of verte- 
brate animals, then we ought perhaps to conclude, with Mr. 
Darwin, that probably all organisms are derived from a single 
prototype. But if, on the other hand, the amount of change 
we can observe either of degradation or elevation^ or both, is 
so limited that no amount of time could account for the di- 
versity of forms of animal and vegetable life we see around 
us, I think we are driven back upon the hypothesis of a 
special creation of species, without being committed to the 
special form or manner of that creation. But, whatever be 
the direction in which our opinions lead us, let us not be 
hasty in the interpretation of the facts which are presented 
to us. Let us observe carefully and cautiously, and record 
our observations faithfully, in the full confidence that the 
Creator has so endowed the human mind, that it will in the 
end reject all that which is false, and only hold that which 
is true. 
I now call your attention to two papers of high interest, on 
the microscopic structure of the nervous system j the one by 
Messrs. Turner and Lister, of Edinburgh^ the other by Mr. 
Lockhart Clarke, of London. To the latter gentleman we 
are indebted for our knowledge of a method of preparing 
nervous tissue for examination, which has resulted in a much 
more accurate knowledge of the details of the structure of the 
