OUTLINE OV CHAPTER IX. 



PROPAGATION OF PLANTS. 



^.— pr()pa(;ation from seeds. 



SEEDS AND SEEDLINGS. 



I. The Seed-coat. 



Stratificatioti. 



II. The Testing of Seeds. 



1. Jmporiancc of Seed-testing. 



2. Purity. 



3. Vitality. 



Factors influencing vitality are : 

 (i) Time of Gathering. 



(2) Condition of Parent Plant. 



(3) Age 



(4) Method of Preservation. 



III. Germination of Seeds. 



A study of the conditions for germinatior 



1. TefJiperature. 



2. Moisture. 



3. Arr. 



4. Geoiropism. 



5. Light. 



6. Other 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. 



{(i) Natural Selection. 

 (/>) Artificial Selection. 



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