The Note-Books of Samuel Butler

The reason why the offspring of protoplasm progressed, and the offspring of nothing else does so, is that the viscid nature of protoplasm allows vibrations to last a very long time, and so very old vibrations get carried into any fragment that is broken off; whereas in the case of air and water, vibrations get soon effaced and only very recent vibrations get carried into the young air and the young water which are, therefore, born fully grown; they cannot grow any more nor can they decay till they are killed outright by something decomposing them.  If protoplasm was more viscid it would not vibrate easily enough; if less, it would run away into the surrounding water.