THE PRESENT POSITION OF CELL-THEORY. 321 



call hypothesis to aid, and it has been my object to avoid 

 the use of hypothesis where I could do without it. It is, 

 however, legitimate to frame an argument which, while it 

 agrees with the lessons of experience, is ultimately based 

 upon hypothetical considerations, provided always that those 

 considerations are consistent with the accepted teaching of 

 the sciences whose aid is invoked. 



Any attempt whatever to find an explanation of vital 

 phenomena ends in an appeal to chemistry and physics. 

 Knowing as we do that the elements of which organic 

 bodies are composed are not different from those which 

 occur in the inorganic world, we cannot refuse to acknow- 

 ledge that vital processes are in the end chemico-physical 

 processes, and this much is conceded by every author of a 

 theory of vital units. The difficulty which they have to 

 face is the same as that which I have to face, and is not one 

 whit the less because it is compressed into the limits of 

 a biophor, whereas I would allow it the limits of a cell. 

 Can we frame any distinct ideas of these chemico-physical 

 processes ? Not very distinct ideas, perhaps, yet we can 

 supplement the lack of positive evidence by analogies and 

 illustrations involving the same ideas as those which are 

 current in the physical world. 



It was Professor W. K. Clifford, I think, who first drew 

 a graphic picture of the molecular forces which are at work 

 in any chemical compound, by describing the atoms as 

 linked to one another and dancing a sort of merry-go-round 

 within circumscribed limits. We may carry on the illustra- 

 tion, which, fanciful though it may seem, is supported by 

 physical and mathematical considerations. A biont is a 

 great organised war dance, performed by a whole army 

 corps. The individuals composing each company are the 

 atoms, they are linked to one another by companies and 

 each company dances its own figure. Every company is a 

 molecule, and every company dance is but a part of a larger 

 dance, in which the companies act in relation to one another 

 as the individuals act in the company dance. The larger 

 dances are regimental dances and every regiment is a 

 micella. The regimental dances are but parts of still larger 



