84. Proceedings of the Royal Physical Society. 
like nervosity in animals. It is interesting to recall the close resemblance 
between plants and zoophytes. They have a very similar kind of beauty— 
expressing the dream-smiles of their sleep-like life. 
Unembarrassed by a too great multitude of facts, Bergson sees the 
broad lines of evolution. “In its evolution movement, life is like a shell 
which suddenly bursts into fragments, which fragments, being themselves 
shells, burst in their turn into fragments destined to burst again, and so on 
for a time incommensurably long.” He points out that life had to begin 
humbly. The resistance, the inertia, the stick-in-the-mud-ness of not-living 
matter had to be overcome. Stooping to conquer, life entered into the 
habits of the inert. But it had a tremendous internal push, and when it 
began to get a certain amount of way on it showed its freedom. Changing 
the metaphor, we see life developing like a sheaf, like a fleur-de-lis, tentatively 
in different directions. Like a very young child it tried many experiments 
and got many bumps. The paths show sinuosities, blind-alleys, turnings 
back, as well as difficulties surmounted. They are neither accidental nor the 
coercive results of environment. Nor can we fit on the frame of finalism, 
for nature is more and better than the realisation of a plan given beforehand. 
Evolution is “a creation that goes on for ever in virtue of an initial movement.” 
With clear insight Bergson sees that the dichotomy which split Organisata 
into plants and animals has often recurred. It divides animals into what 
Prof. Arthur Willey calls Eleutherozoa and Statozoa—the free and the fixed. 
We see the alternative, ever recurrent, in the contrast between active 
Infusorians and passive Sporozoa, between feverish birds and sluggish reptiles. 
Perhaps, as the authors of The Evolution of Sex long ago contended, it is the 
same dichotomy that separates male from female, and masculine from 
feminine characters. 
With clear insight, again, Bergson recognises the extraordinary interest 
that attaches to the early worms—almost the first creatures to have bilateral 
symmetry and the first to have head-brains, beginning the long process which 
has enabled us to tell our right hand from our left. He gives them their due 
those early worms,—‘ infinitely plastic forms, pregnant with an unlimited 
future, the common stock of Echinoderms, Molluscs, Arthropods, and 
Vertebrates.” 
These four great phyla represent the four main directions of the animal 
kingdom above the “worm” level, but only two have become highways, viz. 
the Arthropods and the Vertebrates. 
Perhaps it was the imprisonment in armour that heavily handicapped the 
Echinoderms and Molluscs, as Lucretius suggests in his fine phrase 
“hampered all in their own death-bringing shackles.” At any rate the 
