28 



Principles of Plant Culture. 



boiled long enough to expel the oxygen, and is placed 

 under conditions that prevent its absorption again 

 (Fig. 5). 



We thus see that seeds require three conditions before 

 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 affer it is planted, the better 

 for it is generally in danger of being destroyed by ani- 

 mals or fungi, and the plantlet probably loses vigor by 



too slow develop- 

 ment. Weeds may 

 also be gaining a 

 start i f germiua: 

 tion i s delayed. 

 We should, there- 

 fore, treat both the 

 seed and the soil in 

 the way that fav- 

 ors prompt germi- 

 nation. 



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, hence the rice seeds in it could not germinate. In the right bottle, 

 the water was not covered, and so could absorb oxygen, permitting the 

 seeds to germinate. From nature. 



33. Compacting the Soil about planted seeds Hastens 

 Germination by multiplying their points of contact with 

 the moist earth (276). When the soil is becoming drier 

 day by day, as it often is in spring, compacting the 

 soil about planted seeds materially hastens their germi- 

 nation and often secures germination that without the 



