Organisms aiid Their Origin 95 



"lifeless." But a flash comes from a passing 

 cloud, and the oak is dead. Where is our clear 

 contrast now ? We watch a bird flying overhead : 

 "it rests upon the air, subdues it, surpasses it, 

 outraces it." What a contrast to the stone beneath 

 our feet, which we usually call "inert"! But the 

 stone is thrown, and the bird falls dead. Where is 

 our clear contrast now ? A slight blow on the back 

 of the head, and what we call "life," where is it? 

 It is extremely difficult to find an absolute criterion 

 between what once was living and what now is 

 dead. In many cases, we can obviously say of 

 the killed creature that its machinery is shattered; 

 in other cases, we can only say that the wheels have 

 ceased to go round. A few hours ago the eggs 

 of that bird were living— intensely living— in her 

 nest, but the bird is dead and the eggs are growing 

 cold. Life is slipping away. Take them still 

 and hatch them in the incubator, and you will soon 

 see how really living they are. Take them next 

 day and you might as well take stones. Pro- 

 fessor Waller says there is an electrical "blaze 

 reaction" which will infallibly tell us whether the 

 "vital spark" has gone out in the forsaken egg 

 or in the wind-blown seed, but we do not know 

 much about it. The sure test of livingness or 

 non-livingness is, of course, in results. 



Puzzling Phenomena. — The phenomena of " latent 

 life" are very puzzling, and deserving of far more 



