CHAPTER VI. 

 LABORATORY EXERCISE: FORMS OF LIFE. 



58. Allow the student to collect several different types of living 

 objects, together with all the facts he can find with respect to their 

 food and modes of living. 



The teacher should see that such organisms as the following are 

 brought to his attention: fungi, such as toadstools and shelf- 

 fungi ; bread mold (which may be grown on bread, in a moist chamber 

 formed by a bell-jar inverted over a plate) ; bacteria (which may be 

 grown rapidly by chopping up some hay and placing it in a vessel 

 of water with a small piece of meat the size of a cherry) ; pond-silk, 

 which floats at the surface of quiet ponds; corn and other common 

 plants; any animals, as the earth-worm, the frog, the cow, and man. 



Study these objects somewhat as in Chapter IV. 



59. Organisms may be classed as follows: 



1. Those organisms able to subsist on inorganic food. 



2. Those organisms requiring organic food. 



Do i and 2 together include all possible organisms? 

 Reasons for your answers. Could an organism possibly 

 belong to both at once? Why? Be very careful here: 

 many students are inclined to go astray at this point. 



Which, if any, of the forms of life mentioned and 

 studied in Section 58 seem to you to belong to the first 

 class? Which to the second class? 



Let the teacher, by questioning, bring out what the pupils know 

 about the food requirements of the plants and animals mentioned 

 above, adding, when necessary, facts which will extend the students' 

 knowledge of the experiments that have been made by others. 

 The time is too short for the pupils to verify the water-culture- 

 medium experiments; but the teacher should make the student 

 realize, as though he had made the experiment himself, that the 



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