104 OX THE PHYSICAL BASIS OF LIFE 



the remarkable investigations of De Bary have shown 

 that, in another condition, the sEthalium is an actively 

 locomotive creature, and 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 questionable forms. But, as it is ad- 

 mittedly 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 difficulty 

 which, before, was single. 



Protoplasm, 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 are cog- 

 nate, and that all living forms are fundamentally of one 

 character. The researches of the chemist have revealed 

 a no less striking uniformity of material composition in 

 living matter. 



In perfect strictness, it is true that chemical investi- 

 gation can tell us little or nothing, directly, of the com- 

 position 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 whatever respecting the 

 composition of actually living matter, from that of the 

 dead matter of life, which alone is accessible to us. But 

 objectors of this class do not seem to reflect that it is 



