46 INTERRELATIONS OF PLANTS AND ANIMALS 



Artificial Cross-pollination and its Practical Benefits to Man. 

 Artificial cross-pollination is practiced by plant breeders and can 

 easily be tried in the laboratory or at home. First the anthers 

 must be carefully removed from the. bud of the flower so as to elim- 

 inate all possibility of self-pollination. The flower must then be 

 covered so as to prevent access of pollen from without ; when the 

 ovary is sufficiently developed, pollen from another flower, having 

 the characters desired, is placed on the stigma and the flower 

 again covered to prevent any other pollen reaching the flower. 

 The seeds from this flower when planted may give rise to plants 

 with the best characters of each of the plants which contributed 

 to the making of the seeds. 



REFERENCE BOOKS 



ELEMENTARY 



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

 Andrews, A Practical Course in Botany, pages 214-249. American Book Company. 

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

 Coulter, Plant Life and Plant Uses, pages 301-322. American Book Company. 

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

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

 Needham, General Biology, pages 1-50. The Comstock Publishing Company. 

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

 Sharpe, A Laboratory Manual in Biology, pages 43-48. American Book 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 Com- 

 pany. 



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

 and Company. 



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

 and Company. 



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



Lubbock, British Wild Flowers. The Macmillan Company. 



Muller, The Fertilization of Flowers. The Macmillan Company. 



