28 



Principles of Plant Culture. 



that has been boiled long enough to expel the oxygen, 

 and is placed under conditions that prevent its ab- 

 sorption again (Pig. 5). 



Wie thus see that seeds require three conditions be- 

 fore they can germinate, viz., a certain amount of 

 moisture, of warmth and of oxygen. In planting seeds, 

 we should consider all these requirements. 



32. Prompt Germination is Important. As a rule, 

 the sooner a seed germinates after it is planted, the bet- 

 ter, for it is gen- 

 erally in danger of 

 being destroyed by 

 animals or fungi, 

 and the plantlet 

 probably loses vig- 

 or by too slow 

 developme nt. 

 Weeds may also be 

 gaining a start if 

 germination is de- 

 layed. We should, 

 therefore, treat 

 both the seed and 

 the soil in the way 

 that favors prompt 

 germination. 



33. Compacting the Soil about planted seeds Hastens 

 Germination by multiplying their points of contact 

 with the moist earth {27b). When the soil is be- 

 coming drier day by day, as it often is in spring, 

 compacting the soil about planted seeds materially 



Fig. 5. In the left bottle, the water, 

 which had been boiled to expel the oxygen, 

 was covered with oil to prevent it from 

 absorbing oxygen again, hpnce the rice 

 seeds in it could not germinate. In the 

 right bottle the ^Yate^ was not covered, 

 and so could absorb oxygen, permitting the 

 seeds to germinate. (From nature.) 



