APPENDIX II 173 



CHAPTER XXIII 



SELF- POLLINATION 

 General Reading 

 Kerner and Oliver, Volume II, Part i, pp. 331-401. 



THESE pages give a review of the general subject of self- 

 pollination or Autogamy which results in close- fertilization, 

 a phenomenon of much more frequency than has been gen- 

 erally supposed. 



Gray, Text-book, pp. 240-242. 



I. Weed, Ten New England Blossoms, pp. 90-98 ; Kerner 

 and Oliver, Volume II, Part i, p. 393. 



Species of Polygala with cleistogamous flowers occur over 

 nearly the whole of the United States. Pressed specimens 

 may be used as well as fresh ones. P. polygama is one of 

 the best species, since the cleistogamous flowers are numer- 

 ous and may be obtained in all stages. 



In regard to the cleistogamous flowers of Violets, read 

 Lubbock, Flowers, Fruits, and Leaves, pp. 53-57. 



