PROPERTY AND COMMON SENSE. 135 



understand and act in concert with the bricklayer. 

 As the bricklayer is held to be living and the bricks 

 non-living, so the bones and skin which protoplasm 

 is supposed to construct are held non-living and the 

 protoplasm alone living. Protoplasm, it is said, goes 

 about masked behind the clothes or habits which it 

 has fashioned. It has habited itself as animals and 

 plants, and we have mistaken the garment for the 

 wearer — as our dogs and cats doubtless think with 

 Giordano Bruno that our boots live when we are 

 wearing them, and that we keep spare paws in our 

 bedrooms which lie by the wall and go to sleep when 

 we have not got them on. 



If, in answer to the assertion that the osseous parts of 

 bone are non-living, it is said that they must be living, 

 for they heal if broken, which no dead matter can do, 

 it is answered that the broken pieces of bone do not 

 grow together; they are mended by the protoplasm 

 which permeates the Haversian canals; the bones 

 themselves are no more living merely because they 

 are tenanted by something which really does live, than 

 a house lives because men and women inhabit it ; and 

 if a bone is repaired, it no more repairs itself than a 

 house can be said to have repaired itself because its 

 owner has sent for the bricklayer and seen that what 

 was wanted was done. 



We do not know, it is said, by what means the 

 structureless viscid substance which we call proto- 

 plasm can build for itself a solid bone ; we do not 

 understand how an amoeba makes its test ; no one 

 understands how anything is done unless he can do it 



