THE PROGRESS OF PHYSICS. 175 



Larmor's theory of atoms as loci of strain in the 

 ether, and so on. " So, as we watch the weaving of 

 the garment of Xature, we resolve it in imagination 

 into threads of ether spangled over with beads of 

 matter. We look still closer, and the beads of mat- 

 ter vanish; they are mere knots and loops in the 

 threads of ether." * 



An Analogy. An analogy which has often ap- 

 pealed to our biological mind may possibly make the 

 subject clearer. In Biology we are accustomed to 

 speak of three big facts organism, environment, and 

 function. The environment includes the world of 

 external influences; the organism is the living crea- 

 ture which contains nothing sensible that is not also 

 in the environment; function consists of action and 

 reaction between organism and environment. We do 

 not know the secret of the synthesis which has made 

 it possible for the organism to be a persistent, though 

 ever changeful, a unified and yet reproductive, whirl- 

 pool in the stream of the environment. But there 

 it is. 



Now it may be that molecules, atoms, corpuscles 

 are persistent unities individualised in the stream or 

 ocean of the ether, as the organism is in its environ- 

 ment, the syntheses being secrets in both cases. And 

 it may be that energy corresponds to function, con- 

 sisting of action and reaction between matter and 

 ether. 



SUMMAEY. That matter cannot be conceived as 

 built up of perfectly hard atoms seems quite certain; 

 that it has a heterogeneous structure seems equally 

 certain; some modification of a theory of vortex- 

 atoms would find acceptance as an interpretative 



* J. J. Poynting. Address, Section A, Rep. Brit. Ass. for 

 1899, p. 619." 



