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hardly any that is not under full human control, excepting only minute 

 forms. Yet right in the heart of those old, civilised, and densely popu- 

 lated centres, in the rivers Thames and Seine, life goes on exactly as it 

 did a million, 50 million, even longer ages before, primitive and savage, 

 hide or be eaten, fly or be eaten, eat or be eaten. In no water is life 

 entirely subject to man-made laws. 



After all the work that has been done on the sea, the emergence of the 

 unknown Coelacanth, a large robust creature, does show clearly how 

 little we know, and it brings at least a hope that there may be other 

 primitive forms still surviving somewhere there. It tells us even more. 

 It has shown that comparatively large creatures can live for long ages 

 in the sea and leave no easily accessible fossil traces. It may, and almost 

 certainly does, mean that there have been other creatures who lived 

 always in the sea of which no traces have been found and of which we 

 have no knowledge at all. It leaves a hope that there may still be such 

 unknown forms alive in the sea, and that they may be discovered when 

 man achieves greater mastery of that region beyond the tidal fringe. 

 There is, indeed, probably a greater possibility of this than of the 

 existence of another known type like the Coelacanth. 



It is astonishing how much an intensive study of fossils can tell us 

 about the creatures that left them. Often even habits and other charac- 

 teristics can be deduced. Nevertheless, there are big gaps in our 

 knowledge of past life. We know next to nothing of the soft parts of 

 the early forms of life, nothing of that very early big change-over from 

 invertebrate to vertebrate. 



Flesh (protein) is composed chiefly of remarkable aggregates of 

 substances known as amino-acids, and difl"erent amino-acids in varying 

 proportions are found in the flesh of different animals, while the protein 

 of plants is again very different from that of animals. In the course of 

 evolution, profound changes in amino-acid components of flesh protein 

 may have accompanied other structural modifications. I learnt at the 

 Comores that the flesh of the Coelacanth when cooked becomes jelly- 

 like. It will probably be found to have a composition different from the 

 flesh of ordinary fishes. 



In the course of evolution, there will almost certainly have been 

 continual change in the form of the intestines, in the composition of 

 the digestive fluids and enzymes, and in many of the soft parts. It is 

 unlikely that we shall ever know very much of this, but the Coelacanth 

 holds out a hope of gaining some of that knowledge. 



One of the most outstanding characteristics of the Coelacanths is 

 that they have changed remarkably little during the vast ages they 

 have lived. The bony structures of our modern Coelacanth are almost 

 exactly the same as those left by Coelacanths of several hundred 



