APPENDIX. 179 



the same ; the graining will show a difference to the 

 naked eye. The microscope will show that the wood 

 is not uniform in its smallest parts ; it is what we 

 may term " organised," the structure being different 

 as we shift the eye along the smallest distance of the 

 thinnest section. The same applies to bone and 

 muscle ; in fact, to all parts of the bodies of all 

 animals and plants. The idea, then, of molecule is a 

 conception of an ultimate bit of a substance towards 

 which our experimental breaking has in actual experi- 

 ence partially reduced it, and would never have oc- 

 curred to the ancients had the commonest objects of 

 nature been, like variegated marble or granite, of ob- 

 vious heterogeneous structure. When, therefore, we 

 translate this idea to the realm of biology, where 

 bodies are not made up of similar parts, it is obvious 

 that we do this without warrant, in face of our bio- 

 logical experience, and that we are thoughtlessly ac- 

 cepting a physical theory of gases and incandescent 

 solids without appreciating the foundation upon 

 which this theory rests. The fact of the matter is, we 

 are in utter ignorance as to the ultimate constitution 

 of any living matter; but so far as microscopic in- 

 vestigation goes, we learn that it has unlike not 

 like parts. Our experience, therefore, rather con- 

 tradicts the belief that it will be found to consist of 

 ultimate parts, each part having the function of living 

 protoplasm, biophores, or whatever name may be at- 

 tached to them ; and we recall Clifford's rule that we 

 may believe what goes beyond our experience only 



