260 FIRST YEAR COURSE IN GENERAL SCIENCE 



proteids 



plant by the action of the chlorophyll bodies, aided by the 

 energy of the sun's light. 



With the water from the ground, green plants take mineral 

 matter which has been dissolved in the water. Nitrates 

 and phosphates are mineral matter that is present in most 

 fertile soils. Certain elements of these substances, such as 

 nitrogen and phosphorus, are combined with the elements 

 of sugar and starch, in green, plants, to make proteid, 



another food. Protoplasm 

 is made of proteid. 



287. The Relation of 

 Plants to Animals. Earth, 

 air, and water contain all 

 the elements necessary to 

 the growth of plants and 

 animals, but no animal can 

 use these in preparation of 

 food. The protoplasm of 

 green plants, with the 

 energy of sunlight, makes 

 food which is used by 

 animals as well as by 

 plants. Animals feed upon 

 plants in which food has 

 been made, or upon other 

 animals which have fed 

 upon plants. Animals cannot exist without green plants. 

 On the other hand, the waste product of animals, carbon 

 dioxide, is absolutely necessary to plants for food manufac- 

 ture. 



Animals that eat plants only are herbivorous ; those that 

 live upon other animals only are carnivorous; while those 

 that eat both plant and animal food are omnivorous. The 

 food of a sheep and of a lion can be traced to the same source. 

 The food of a sheep is proteid matter and starch found in 



FIG. 136. RELATION BETWEEN 

 PLANTS AND ANIMALS 



1. Which of the six substances 

 named on the circle can be obtained 

 from earth and air? 2. How are the 

 others provided? 3. Read this diagram 

 so as to express the dependence of one 

 kind of organism upon the other. 



