OCR Text |
Show {) THE PRESEXT CO~DITIO~ And here, as it will always happen when dealing with au extensive subject, the greater part of my course-if~ indeed, so small a number of lectures can be properly called a course- n1ust be devoted to preliminary matters, or rather to a statement of those facts and of those principles which the work itself dwells upon, and brings more or less directly before us. I have no right to suppose that all or any of you are naturali~ts; and even if you were, the misconceptions and misunderstandings prevalent even among naturalists on these matters would make it desirable that I should take the course I now propose to take,-that I should start from the beginning,-that I should endeavour to point out what is the existing state of the organic world-that I should point out its past condition,-that I should state what is the precise nature of the undertaking which ~1r. Darwin has taken in hand; that I should endeavour to show you what are the only methods by which that undertaking can be brought to an issue, and to point out to you how far the author of the work in question has satisfied those conditions, how far he has not satisfied them, how far they are satisfiable by man, and how far they are not satisfiable by man. And for to-night, in taking up the first part of this question, I shall endeavour to put before you a sort of broad notion of our knowledge of the condition of the livino· b world. There are many ways of doing this. I might deal with it pictorially and graphically. Following the exa~ple of Humboldt in his "Aspects of Nature," I m1g~t ~nd~avour to point out the in finite variety of organ1c hfe rn every mode of its existence, with reference to the variations of climate and the like ; and such OF ORGANIC NATURE. 7 an attempt would be fraught with interest to us all; but considering the subject before us, such a course would not be that best calculated to assist us. In an argument of this kind we must go further and dig deeper into the matter; we must endeavour to look into the foundations of living Nature, if I may so say, and discover the principles involved in some of her most secret operations. I propose, therefore, in the first place, to take some ordinary animal with which you are all familiar, and, by easily comprehensible and obvious examples drawn from it, to show what are the kind of problems which living beings in general lay before us ; and I shall then show you that the same problems are laid open to us by all kinds of living beings. But, first, let me say in what sense I have used the words " organic nature." In speaking of the causes which lead to our present knowledge of organic nature, I have used it almost as an equivalent of the word "1"r v.r ng, " an d 1~ 0r t h"r s reason,-that in almost all living beings you can distinguish several distinct portions set apart to do particular things and work in a particular way. These are termed "organs," and the whole together is called " organic." And as it is universally characteristic of them, this term "organic'' has been very conveniently employed to denote the whole of living nature,-the whole of the plant world, and the whole of the animal world. Few animals can be more familiar to you than that whose skeleton is shown on this diagram. You need not bother yourselves with this "Equus caballus" written under it; that is only the Latin name of it, and does not make it any better. It simply means the |