844 LIFE : OUTLINES OF GENERAL BIOLOGY 



important constituents of living matter or protoplasm, are linkages 

 of amino-acids, and these amino-acids can be built up syntheti- 

 cally. The probability is that the artificial synthesis of proteins will 

 be achieved. 



The difficulty is to picture how this synthesis might be effected 

 in natural conditions upon the earth, — a difficulty that is increased 

 by the fact that there does not seem to be any even approximately 

 analogous process going on at present. It is possible, however, that 

 it may have occurred in different conditions when the earth was 

 younger. It is also possible that natural synthesis still continues 

 apart from life, though it has not been detected. 



Some physiologists have looked to cyanogen (CN) as possibly 

 affording a starting-point in the hypothetical synthetic process 

 leading on to protoplasm. Cyanogen and its compounds may be 

 formed in incandescent heat, and might arise while the earth was 

 still hot. The cyanogen compounds are unstable and might readily 

 form linkages with other compounds, especially when water began to 

 be precipitated on the cooling crust of the earth. 



More promising, perhaps, is the hint afforded by the experiments 

 of Baly, which have shown the possibility of using light-rays so as 

 to produce from water and carbon dioxide the sugar that is built 

 up in the green leaf. By adding a nitrogen compound, a further 

 sjoithesis was effected. As nitrate of ammonia or something similar 

 might be carried by a thunder-shower into a sunlit pool with carbon 

 dioxide in the water, it is possible that nitrogenous carbon com- 

 pounds might be synthesised in natural conditions. 



"It may be objected that our problem is not the origin of living 

 matter or protoplasm merely, such as we might squeeze out of a 

 sponge or some similar simple animal, but the origin of a living 

 creature, an organism, a viable unity. What can one answer save 

 that the tendency to integration, hypothetically manifested in the 

 synthesis of protoplasm, may have continued into the integration 

 which led to the first organisms? These were probably very short- 

 lived, perhaps only creatures of a day, dying, as they multiplied, 

 in the cold of their first night. But their radical distinction from the 

 non-Uving was that they were going concerns, able to balance their 

 matter-and-energy accounts for at least a short time. It is probable 

 that it was during this integration of the first organisms that mind 

 emerged, in flashes at least. One may perhaps ask whether the 

 difficulty of the problem of the origin of living creatures may not 

 be due in great part to the _/)s>'c/^o-biological nature of the momentous 

 integration." (Thomson, Concerning Evolution, 1925, p. 47.) 



THE FIRST ORGANISMS.— This inquiry must be essentially 

 a speculative one, yet it may not be unprofitable to try to picture 

 the first organisms. Not much help can be got from the study of 



