584 SCIENCE PROGRESS 



phcrised protein or nuclein, nor how this substance acquires 

 the capacity of auto-synthesis or reproduction, which makes it 

 alive. But it is now fairly clear that it is through a series of 

 complications and chemical differentiations akin to that by 

 which, for example, the endless varieties of precious stones, 

 sapphires, rubies, emeralds, topaz, chrysoprase, have been 

 synthesised in the earth beneath our feet. 



Probably it will be a very long time before we shall be 

 able to take a simple organism, a fungus or a protozoan, and 

 turn this at will into a star-fish or an oyster. Doubtless the 

 generality of biologists believe that this will never be possible. 

 Still less may we hope, perhaps, to convert a protozoan into 

 a fish, a bird, or a man. But it is not at all inconceivable that 

 we shall some day, and perhaps not distantly, mix in a test 

 tube a substance which will indefinitely reproduce itself from 

 non-living materials, and this will be the creation of life. 



Herein, perhaps, we have a picture, and a measure, of the 

 amount of mystery involved in the familiar and accepted fact 

 of evolution, as contrasted with that of the organisation of 

 non-living into living matter. And if in this we do not err, 

 it is evident that the natural origin of life on the earth is 

 not an insoluble riddle, and that even now it is possible, in 

 a broad way, to realise the conditions under which this 

 evolution from the inorganic took place. 



Clearly to state a problem, it is often remarked, is half 

 its solution. It has not been possible, until the most recent 

 achievements of bio-chemistry, to state the problem of the 

 initial appearance of life with any clearness at all. Until very 

 recently it was not known what "protoplasm" is. Until 

 very recently it was not known how inorganic substance might 

 be built up into compounds closely resembling the basic sub- 

 stances of protoplasm. It was for this reason that any theory 

 as to the origin of life was, until the year 1906, for all 

 practical purposes nothing but a confused guess. 



In the light of our new knowledge, we may state the 

 problem in the following precise form : 



1. Under what conditions did carbon dioxide or some other 

 carbon compound unite with water to form formaldehyde or 

 other simple carbohydrate, and how did this carbohydrate 

 react with a nitrogen-containing substance like ammonia or 

 prussic acid, to form amino acids? 



