THE president's ADDRESS. 355 



<liversity of character which we see in living things at the present 

 time, and whicli we know also, from the evidence of palaeontology, 

 to have existed through many past ages of the world's history. 

 To put it in one sentence, life on our earth must have had a 

 beginning. If that be admitted, there are then two possibilities 

 the first that the life known to us originated on the earth itself, 

 iihe second that it was introduced in some way to our planet 

 from without. 



It has been, I think I may say, the view held by the majority 

 of naturalists that terrestrial life originated on the earth itself 

 at an epoch when the earth was cooled down suthciently to admit 

 the possibility of living things existing on it. This view has been 

 put forward by Sir Ray Lankester. I cannot do better than 

 <][uote his exact words, as follows : 



" A very interesting and difficult subject of speculation ... is 

 the nature of the first protoplasm which was evolved from not- 

 living matter on the earth's surface. ... A conceivable state of 

 things is that a vast amount of albuminoids and other such com- 

 pounds had been brought into existence by those processes which 

 culminated in the development of the first protoplasm, and it 

 seems therefore likely enough that the first protoplasm fed upon 

 these antecedent steps in its own evolution just as animals feed 

 on organic compounds at the present day, more especially as the 

 large creeping plasmodia of some Mycetozoa feed on vegetable 

 refuse. . . . At subsequent stages in the history of this archaic 

 matter chlorophyll was evolved and the power of taking carbon 

 from carbonic acid. The 'green' plants were rendered possible 

 by the evolution of chlorophyll, but through what ancestral forms 

 they took origin . . . it is difficult even to guess " {Encyclo2xiedia 

 Britannica, 9th edition, art. " Protozoa "). 



If we try to realise in imagination the speculations conveyed 

 in this passage, we may suppose that there was a period when 

 the earth, though far hotter than at present, had cooled down to 

 ^ certain temperature, sufficiently low for the formation of a firm 

 though thin crust, and to permit of precipitation of water-vapour 

 upon it. The thin crust of the earth was probably continually 

 shrinking, cracking, upheaving, and allowing molten masses to 

 escape from its interior on to the surface ; such upheavals, in 

 fact, as we see at the present time on a vastly smaller scale in 

 volcanic eruptions. These cataclysms would cause rapid and 



JouRN. Q. M. C, Series II. No. 70. 24 



