OUTLINE OF CHAPTER IX. 



PROPAGATION OF PLANTS. 



^.PROPAGATION FROM SEEDS. 



SEKDS AND SEEDLINGS. 



1. The Seed-coat. 



Strjtification. 



5.1. The Testing of Seeds. 



1. Importance of Seed-testing. 



2. Purity. 



3. Vitality. 



Factors influencing vitality are : 



(1) TIMK OF GATHERING. 



(2) CONDITION OF PARENT PLANT. 



(3) AGE 



(4) METHOD OF PRESERVATION. 



(II. Germination of Seeds. 



A study of the conditions for germinalior 

 r. Temperature. 



2. Moisture. 



3. Air. 



4. Qeotropism. 

 5- Light. 



6. OtJier Conditions. 



IV. Treatment of Fine Seeds. 



V. Variation of Plants. 



1. Causes of Variation. 



(1) DIFFERENCE IN FOOD SUPPLY 



(2) CLIMATIC CONDITIONS. 



(3) SEXUAL REPRODUCTION. 



2. Fixation of Variation. 



(i) MEANS. 



(a) Natural Selection. 



(b) Artificial Selection. 



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