2 THE PHYSICAL BASIS OF LIFE 



posedly materialistic implications, it aroused immediate 

 and widespread public attention. Huxley himself warned 

 that to accept his conclusions would be to place one 's foot 

 on the first rung of a ladder which in most people's esti- 

 mation is the reverse of Jacob 's and leads to the antipodes 

 of heaven ; nevertheless, he insisted that he was individu- 

 ally no materialist but on the contrary believed materi- 

 alism to involve grave philosophic error. Despite this dis- 

 claimer, his conclusions aroused a storm of criticism and 

 protest which came to a climax a few years later when 

 Tyndall, in the famous Belfast address, proclaimed his 

 faith in non-living matter as offering the "promise and 

 potency of all terrestrial life."" 



It is not surprising that such pronouncements should 

 have had a hostile reception fifty years ago. Even in this 

 twentieth century some of our non-scientific friends 

 somehow manage to find a source of heat and fury in so 

 evident a fact as organic evolution. On the whole, how- 

 ever, sane and well-informed persons do not now seem to 

 find either their morals or their happiness seriously 

 affected by elementary and fundamental facts concerning 

 living things. Today Huxley's heresy of sixty years ago 

 has become an orthodox platitude; l3ut the problems of 

 protoplasm still hold us fast with a gripping interest that 

 has lost nothing of its force with the flight of time. In 

 what light do Huxley's conclusions appear after the bio- 

 logical progress of half a century ? 



It is necessary to bear in mind that those conclusions 

 were formulated before modern cytology had been born, 

 and long before the cell had been clearly thought of as a 

 colloidal system. From our present point of view we em- 

 ploy the word protoplasm as a collective term to designate 

 the substances that constitute the active or living materi- 

 als of which cells are composed. I use the plural form. 



