FUNCTIONS OF LIVING THINGS 57 



new." Some prolific plants, like the milkweed, have seeds with a 

 little tuft of hairlike down which allows them to be carried by the 

 wind. Others, as the omnipresent dandelion, have their fruits 

 provided with a similar structure, the pappus. Some plants, as 

 the burdock and clotbur, have fruits provided with tiny hooks 

 which stick to the hair of animals, thus proving a means of trans- 

 portation. Most fleshy fruits contain indigestible seeds, so that 

 when the fruits are eaten by animals the seeds are passed off from 

 the body unharmed and may, if favorably placed, grow. Nuts of 

 various kinds are often carried off by animals, buried, and for- 

 gotten, to grow later. Such are a few of the ways in which seeds 

 are scattered. All other things being equal, the plants best 

 equipped to scatter seeds or fruits are those which will drive out 

 other plants in a given locality. Because of their adaptations 

 they are likely to be very numerous, and when unfavorable con- 

 ditions come, for that reason, if for no other, are likely to survive. 

 Such plants are best exemplified in the weeds of the grassplots 

 and gardens. 



REFERENCE BOOKS 



ELEMENTARY 



Hunter, Laboratory Problems in Civic Biology. American Book Company. 

 Andrews, A Practical Course in Botany, pages 250-270. American Book Company. 

 Atkinson, First Studies of Plant Life, Chaps. XXV-XXVI. Ginn and Company. 

 Bailey, Lessons with Plants, Part III, pages 131-250. The Macmillan Company. 

 Coulter, Plant Life and Plant Uses. American Book Company. 

 Dana, Plants and their Children, pages 187-255. American Book Company. 

 Lubbock, Flowers, Fruit, and Leaves, Part I. The Macmillan Company. 

 Newell, A Reader in Botany, Part II, pages 1-96. Ginn and Company. 



ADVANCED 



Bailey, Plant Breeding. The Macmillan Company. 



Campbell, Lectures on the Evolution of Plants. The Macmillan Company. 



Coulter, Barnes, and Cowles, A Textbook of Botany, Part II. American Book 



Company. 



Darwin, Different Forms of Flowers on Plants of the Same Species. Appleton. 

 Darwin, Fertilization in the Vegetable Kingdom, Chaps. I and II. Appleton. 

 Darwin, Orchids Fertilized by Insects. D. Appleton and Company. 

 Miillor, The Fertilization of Flowers. The Macmillan Company. 



