Chapter Iii. 1. Explain Heredity As the Conservative Force of Nature.

2. Explain Variation as the progressive tendency in nature. 3. In what ratio is the Multiplication of animals? 4. How does the process of Selection make for the survival of the fittest? 5. What three possibilities are open to animals under a change of environment? 6. What is the history of the English Sparrow in this country, and how is his increase accounted for by his powers of adaptation?