lxxii REPORT — 1877. 



tion, all naturalists will now concur in one important principle, viz. that 

 as truthful observation and candid judgment must alone be our guides in the 

 interpretation of Nature, that theory of Creation is best deserving of our 

 adoption which is most consistent with the whole body of facts carefully 

 observed and compared. 



To attempt to trace, within the limits to which my remarks must be con- 

 fined, the influence which the progress of knowledge has exercised upon the 

 scientific and general conception of biological doctrines would be impossible, 

 for the modification of opinion on these subjects has proceeded not less 

 from the rapid advance which our age has witnessed in the progress of 

 general science, especially of physics and chemistry, than from that in the 

 department of biology itself. 



Thus, to go no further than the most general laws of nature, the whole 

 doctrine of the conservation and transmutation of force in Physics, so ably 

 expounded to this Association by Mr. Justice Grove, the theory of com- 

 pound radicals and substitution, with the discovery of organic synthesis, in 

 Chemistry, and the more recent advance in speculation with regard to the 

 molecular constitution and properties of matter, with which we must asso- 

 ciate the names of our last President and of Clerk Maxwell, in completely 

 changing the aspect of physical and chemical sciences within the last thirty- 

 five years, have paved the way for views of the constitution and action of 

 organized bodies very different from those which could be formed at the time 

 of the first Meeting of the Association in this place. And if, confining our- 

 selves to the department of Biology, we note the discovery by microscopical 

 observation of the minuter elementary forms of organization, more especially 

 as flowing from the comprehensive views of organized structure promulgated 

 by Schleiden and Schwann nearly forty years ago, the later discovery and 

 investigation of living protoplasmic substances, the accumulated evidence of 

 progressive and continuous types of animal and vegetable forms in the suc- 

 cession of superimposed strata composing the crust of the earth, the recent 

 discoveries as to the conditions of life at great depths in the ocean, the vast 

 body of knowledge brought together by the labours of anatomists and phy- 

 siologists as to the structure and functions of almost every plant and animal, 

 and (still more, perhaps, than any other single branch of biological inquiry) 

 if we note the rapid and immense progress which has been made during the 

 last fifty years in the study of the entirely modern science of the develop- 

 ment of individual living beings, 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 deduced as to their mutual relations and general nature. 



It is now familiarly known that almost all (if not, indeed, all) the plants 



