Ecologic Study of Living Organisms 621 



A. Heredity 



B. Envdronment < 



1. Physical 

 factors 



2. 



Chemical 

 factors 



3. 



Biologic 

 factors 



4. 



Human 

 factors 



'1. The specific genes (factors) of the organism being studied. 



2. The inherited abilities and reactions of the organism. 



3. Mutations and the production of new types of organisms. 



4. Inheritance of specific structures by an organism. 

 ^5. Rates of metabolism of the organism. 



Temperature 

 Light 

 Wind 

 Gravity 



Alternate recurrence of day and night 

 Physical makeup of the soil 

 g. Slope of soil as affecting the drainage 

 and exposure to light and heat 

 Pressure 



Currents of air and water 

 Presence or absence of natural barriers 

 Presence or absence of natural methods 

 of dispersal 



Quantity and quality (chemical com- 

 position) of the soil 

 Quantity and quality of water (mois- 

 ture) 



Quantity and quality of the atmosphere 

 (oxygen, carbon dioxide, etc.) 

 Quantity and quality of usable foods 

 Ease and efficiency with which waste 

 materials can be removed from around 

 the organism 



Competition between different kinds of 

 animals (or plants) or even the same 

 kinds of animals (or plants), for foods, 

 light, moisture, space, etc. 



b. Competition between sexes (animals) 



c. Dependence of certain types of plants 

 on insects for pollination 



d. Mutual help, such as symbiosis, com- 

 mensalism 



e. Parasitism, saprophytism, predacious- 

 ness 



Dissemination and destruction of plants 

 and their seeds by animals 

 Plants contributing usable foods and 

 oxygen 



-Plants detrimental to certain animals 

 Plants affording shelter, protection, and 

 concealment for animals 



'a. Animal and plant quarantine regula- 

 tions 

 b. Transportation of animals or plants by 

 automobiles, trains, ships, airplanes, etc. 

 Usefulness and domestication of certain 

 types of animals or plants not only 

 influence their distribution, but also the 

 distribution of other organisms around 

 them 



Detrimental animals and plants are de- 

 stroyed at the hands of man which per- 

 mits other types to take their place 



a. 

 b. 

 c. 

 d. 

 e. 

 f. 



h. 

 i. 



J- 

 k. 



a. 



c. 



d. 

 e. 



a. 



■< 



f. 



g- 



h. 

 i. 



c. 



