guykr] THE QUEST/ON OE .METHOD IN NA TOE E- STUDY 235 



II. TO CARE FOR OFFSPRING 



a. Propagation. Seed, slips, runners, etc. 



b. Protection. Burrs, nuts, green fruit, etc. 



c. Storage of food. 



d. Provisions for distribution of seed or spores. 



1 . By animals (fruits, burrs, hooks, nuts, etc.). 



2. By wind (floats, wings, tumble-weed, etc.). 



3. By water. 



4. Other devices (plants which shoot off spores or seed, self-pro- 

 pelling devices, etc.). 



Finally, if the parallel between the business of plants and the 

 business of animals is pursued still farther, it will be apparent that 

 almost all of the questions indicated for the study of animal life 

 are equally applicable to plant life. 



