190 JOURNAL OF THE PLYMOUTH INSTITUTION. 
its various departments so minute and searching, that it will soon 
become impossible, if it is not already so, to describe, much less to 
discuss, within the limits allowed to the President’s address, all that 
may have been discovered from time to time in Chemistry, Geology, 
Geography, and other branches of science. 
This is the opinion of Dr. Thompson, for in justifying the course 
adopted in his address he thus summarises the work before him: 
‘‘ Tf, confining ourselves to the department of Biology, we add the 
discovery by microscopical observation of the minuter elementary 
forms of organisation, the later discovery and investigation of living 
protoplasmic substances, the accumulated evidence of progressive 
types of animal and vegetable forms in the succession of super- 
imposed strata composing the crust of the earth, the recent 
discoveries as to conditions of life at great depths of the ocean, 
the vast body of knowledge brought together by the labours of 
anatomists and physiologists as to the structure and functions of 
almost every plant and animal... .we shall be able to form 
some conception of the enormous extension in our time of the 
basis of observation and fact, from which biological phenomena 
may now be surveyed, and from which just views may be formed 
as to their mutual relations and general nature.” 
If this were not so, there are obvious advantages in the course 
adopted by the President. In him, as in most of his predecessors 
in that honourable office, we have a man who has devoted the best 
of his life and ability to a special subject; he is therefore of all 
others best able to expound that subject, and to report to his fellow- 
workers in other departments the latest results of his investigations. 
It may be said that all this will be secured by publication in another 
way, and at another time, while the miscellaneous character of the 
audience on such an occasion must render the careful treatment of 
any special subject uninteresting, and perhaps unintelligible, to 
many present. But it is fairly replied, that the British Association 
is a Society for the learned, and not for the unlearned; for the 
extension, not the diffusion, of scientific knowledge. It appeals to 
those who have themselves learned the value of patient investiga- 
tion, and who are willing to yield to enquirers in one branch of 
science the consideration and patience which they in turn demand 
for themselves. Further, the instant and wide publicity, through 
the agency of the press, which is secured by the announcement of 
any new discovery from the President’s chair, will, in the estima- 
