GERMINAL OR LINING MATTER, 

 AND FORMED MATTER. 



OTHING that lives is alive in every part Pro- 

 bably no one would maintain that the shell of 

 an oyster or mussel, for example, was, like the 

 living moving mollusk itself, in a living state. Never- 

 theless, the shell grows, but upon careful examination 

 it will be found that growth is restricted to certain 

 points. It grows at the free edge and upon the inner 

 surface, and thus increases in dimensions. By far the 

 greater part of the shell, therefore, is as lifeless while it yet 

 remains connected with the living animal as after it has 

 been preserved in our cabinet. The new matter which 

 is added to it by the living creature is prepared and 

 formed through the instrumentality of living matter. In 

 man, and the higher animals, the free portions of the 

 nails and hair, the outer part of the cuticle, and a por- 

 tion of the dental tissues, are evidently lifeless. But the 

 waste and removal of these is compensated for to a great 

 extent by the addition of new matter by living particles. 

 Of the internal tissues a great part is also in a non-living 

 condition, and it therefore becomes necessary in all in- 

 quiries concerning the nature of the changes and actions 

 taking place in living beings, to determine at the outset, 

 what parts of these beings are in a living state, and what 



