88 SCIENCE PRIMERS. [MATERIAL 



foundation of both the animal and the plant is the 

 proteid united with water; though it is probable 

 that, in all animals and plants, these are associated 

 with more or less fatty and amyloid (or starchy 

 and saccharine) substances, and with very small 

 quantities of certain mineral bodies, of which the 

 most important appear to be phosphorus, iron, 

 lime, and potash. 



Thus there is a substance composed of water 

 + proteids + fat + amyloids + mineral matters 

 which is found in all animals and plants ; and, when 

 these are alive, this substance is termed protoplasm. 



60. What is meant by the word Living ? 

 The- wheat plant in the field is said to be a living 



thing; the fowl running about the farmyard is also 

 said to be a living thing. If the plant is plucked up, 

 and if the fowl is knocked on the head, they soon die 

 and become dead things. Both the fowl and the 

 wheat plant, as we have seen, are composed of the 

 same elements as those which enter into the com- 

 position of mineral matter, though united into com- 

 pounds which do not exist in the mineral world. Why 

 then do we distinguish this matter when it takes the 

 shape of a wheat plant, or a fowl, as living matter ? 



61. The Living Plant increases in Size, by 

 adding to the Substances which compose its 

 Body, like Substances ; these, however, are 

 not derived from without, but are manu- 

 factured within the Body of the Plant from 

 simpler Materials. 



In the spring, a wheat-field is covered with small 



