160 THE BEGINNINGS OF LIFE. 



instruments but indications that they are no more 

 the producers of the vital phenomena, than the shells 

 scattered in orderly lines along the sea-beach are the 

 instruments by which the gravitative force of the moon 

 acts upon the ocean. Like these, the cell marks only 

 where the vital tides have been, and how they have 

 acted/ 



Professor Huxley's doctrine must be distinguished 

 from another put forward by Dr. Hughes Bennett shortly 

 afterwards 1 , and then more fully in the < Proceedings 

 of the Royal Society of Edinburgh,' in 1861. This is 

 more especially known as c The Molecular Theory of 

 Organization/ c The first step/ Professor Bennett says, 

 c in the process of organic formation, is the production 

 of an organic fluid ; the second, the precipitation in it 

 of organic molecules, from which, according to the 

 molecular law of growth, all other textures are derived 

 either directly or indirectly/ So that c the ultimate 

 parts of the organism are not cells nor nuclei, but the 

 minute molecules from which these are formed. They 

 possess independent physical and vital properties, which 

 enable them to unite and arrange themselves so as to 

 produce higher forms. Among these are nuclei, cells, 

 fibres, and membranes, all of which may be produced 

 directly from molecules. The development and growth 

 of organic tissues is owing to the successive formation 

 of histogenetic and histolytic molecules. The breaking 



1 ' Report of the British Association,' 1855, p. 119. 



