I.] THE DURATION OF LIFE. 35 



and indestructible are alone without beginning, then the non- 

 eternal and destructible must have had a beginning. But the 

 organic world is certainly not eternal and indestructible in that 

 absolute sense in which we apply these terms to matter itself. 

 We can, indeed, kill all organic beings and thus render them 

 inorganic at will. But these changes are not the same as those 

 which we induce in a piece of chalk by pouring sulphuric acid 

 upon it ; in this case we only change the form, and the inor- 

 ganic matter remains. But when we pour sulphuric acid upon 

 a worm, or when we burn an oak tree, these organisms are not 

 changed into some other animal and tree, but they disappear 

 entirely as organized beings and are resolved into inorganic 

 elements. But that which can be completely resolved into 

 ' inorganic matter must have also arisen from it, and must owe 

 \ its ultimate foundation to it. The organic might be considered 

 eternal if we could only destroy its form, but not its nature. 



It therefore follows that the organic world must once have 

 arisen, and further that it will at some time come to an end. 

 Hence we must speak of the eternal duration of unicellular 

 organisms and of reproductive cells in the Metazoa and Meta- 

 phyta in that particular sense which signifies, when measured 

 by our standards, an immensely long time. 



Yet who can maintain that he has discovered the right answer 

 to this important question ? And even though the discovery 

 were made, can any one believe that by its means the problem 

 of life would be solved ? If it were established that spontaneous 

 generation did actually occur, a new question at once arises as 

 to the conditions under which the occurrence became possible. 

 How can we conceive that dead inorganic matter could have 

 come together in such a manner as to form living protoplasm, 

 that wonderful and complex substance which absorbs foreign 

 material and changes it into its own sul)Stance, in other words 

 grows and multiplies ? 



And so, in discussing this question of life and death, we come 

 at last— as in all provinces of human research — upon problems 

 which appear to us to be, at least for the present, insoluble. 

 In fact it is the quest after perfected truth, not its possession, 

 that falls to our lot, that gladdens us, fills up the measure of our 

 life, nay ! hallows it. 



D 2 



