^ 2 ELEMENTARY ZOOLOGY. 



41. Generalizations, or Statements of General Truths 

 or Principles. Do the following general statements seem 

 proper inferences to draw from your studies? 



1 . Objects, i. e., " forms of matter," are found in nature, 

 in at least four types: (a) amorphous, without definite 

 or predicable form; (b) crystalline, regularly bounded 

 by plane surfaces and straight lines, coming together at 

 more or less definite angles; (c) non-living products of 

 life; and (d) living objects. 



2. Living objects and the organic products of life have 

 a degree of differentiation into regions or parts which 

 is not possessed by the other classes. 



3. Some classes of objects seem to take their par- 

 ticular form as the result of external activities (pebbles) ; 

 others appear to have some inward control over the 

 shape which the whole assumes (crystals, plants, etc.). 



4. Non-living matter, brought together by the life 

 processes (shells), seems to have some of the complexity 

 of form which characterizes living objects themselves. 



5. There are two classes of organized matter shells 

 and organisms. 



Make other similar generalizations, being careful to 

 base them on your former work. 



42. Testing Former Generalizations by Renewed Ob- 

 servations. Is a study of six classes of objects, in the 

 way in which we have been studying them, sufficient to 

 enable us to make a complete statement of the differences 

 between organic and inorganic objects? or between living 

 and non-living? Why? 



Could you substitute four classes of objects for the 

 sand, pebbles, crystals, and shells that could have beer 

 used in our exercise to illustrate the same general truths 



