SUGGESTIONS.--The pupil should study any plant, or branch of a plant, with reference to the position or condition under which it grows, and compare one plant or branch with another. With animals, it is common knowledge that every animal is alert to avoid or to escape danger, or to protect itself. =2.= It is well to begin with a branch of a tree, as in Fig. 1. Note that no two parts are alike (Chap. I). Note that some are large and strong and that these stand farthest towards light and room. Some are very small and weak, barely able to live under the competition. Some have died. The pupil can easily determine which ones of the dead branches perished first. He should take note of the position or place of the branch on the tree, and determine whether the greater part of the dead twigs are toward the center of the tree top or toward the outside of it. Determine whether accident has overtaken any of the parts. =3.= Let the pupil examine the top of any thick old apple tree, to see whether there is any struggle for existence and whether any limbs have perished. =4.= If the pupil has access to a forest, let him determine why there are no branches on the trunks of the old trees. Examine a tree of the same kind growing in an open field. =5.= A row of lettuce or other plants sown thick will soon show the competition between plants. Any fence row or weedy place will also show it. Why does the farmer destroy the weeds among the corn or potatoes? How does the florist reduce competition to its lowest terms? what is the result? CHAPTER III THE SURVIVAL OF THE FIT The plants that most perfectly meet their conditions are able to persist. _They perpetuate themselves._ Their offspring are likely to inherit some of the attributes that enabled them successfully to meet the battle of life. _The fit_ (those best adapted to their conditions) _tend to survive_. Adaptation to conditions depends on the fact of variation; that is, if plants were perfectly rigid or invariable (all exactly alike) they could not meet new conditions. Conditions are necessarily new for every organism. _It is impossible to picture a perfectly inflexible and stable succession of plants or animals._ =Breeding.=--_Man is able to modify plants and animals._ All our common domestic animals are very unlike their original ancestors. So all our common and long-cultivated plants have varied from their ancestors. Even in some plants that have been in cultivation less than a century the change is marked: compare the common black-cap raspberry with its common wild ancestor, or the cultivated blackberry with the wild form. [Illustration: FIG. 5.--DESIRABLE AND UNDESIRABLE TYPES OF COTTON PLANTS. Why?]