90 SCIENCE PRIMERS. [MATERIAL 



Moreover the new matter, by the addition of which 

 the plant grows, is not applied to its outer surface, but 

 is manufactured in its interior ; and the new molecules 

 are diffused among the old ones. 



62. The Living Plant, after it has grown 

 up, detaches part of its Substance, which 

 has the Power of developing into a similar 

 Plant, as a Seed. 



The grain of wheat is a part of the flower of the 

 wheat plant, which, when it becomes ripe, is easily 

 separated. It contains a minute and rudimentary 

 plant ; and, when it is sown, this gradually grows, or 

 becomes developed into, the perfect plant, with its 

 stem, roots, leaves and flowers, which again give rise 

 to similar seeds. No mineral body runs through a 

 regular series of changes of form and size and then 

 gives off parts of its substance which take the same 

 course. Mineral bodies present no such develop- 

 ment and give off no seeds or germs. They do not 

 reproduce their kind. 



63. The Living Animal increases in Size by 

 adding to the Substances which compose its 

 Body, like Substances ; these however are 

 chiefly derived directly from other Animals 

 or from Plants. 



The fowl in the farmyard is incessantly pecking 

 about and swallowing now a grain of corn, and now 

 a fly or a worm. In fact, it is feeding, and, as every 

 one knows, would soon die if not supplied with food. 

 It is also a matter of every day knowledge that it 

 would not be of much use to give a fowl the soil of 

 a corn-field, with plenty of air and water, to eat 



