142 "X THE PHYSICAL BASIS OF LIFE ni 



takes in solid matters, upon which, apparently, it 

 feeds, thus exhibiting the most characteristic 

 feature of animality. Is this a plant ; or is it an 

 animal ? Is it both ; or is it neither ? Some 

 decide in favour of the last supposition, and 

 establish an intermediate kingdom, a sort of 

 biological No Man's Land for all these question- 

 able forms. But, as it is admittedly impossible 

 to draw any distinct boundary line between this 

 no man's land and the vegetable world on the one 

 hand, or the animal, on the other, it appears to 

 me that this proceeding merely doubles the diffi- 

 culty which, before, was single. 



1'rotoplasm, simple or nucleated, is the formal 

 basis of all life. . It is the clay of the potter: 

 which, bake it and paint it as he will, remains 

 clay, separated by artifice, and not by nature, from 

 the commonest brick or sun-dried clod. 



Thus it becomes clear that all living powers arc- 

 cognate, and that all living forms are fundamen- 

 tally of one character. The researches of the 

 chemist have revealed a no less striking uni- 

 formity of material composition in living matter. 



In perfect strictness, it is true that chemical in- 

 vestigation can tell us little or nothing, directly, of 

 the composition of living matter, inasmuch as such 

 matter must needs die in the act of analysis, and 

 upon this very obvious ground, objections, which I 

 confess seem to me to be somewhat frivolous, have 

 been raised to the drawing of any conclusions 



