THE LIFE AND GROWTH OF SEEDLINGS 15 



axle of the minute hand a disc of metal or wood, faced with 

 cork about 3 inches in diameter, so that it will revolve in a 

 plane parallel to the face of the clock. A moist chamber may be 

 then made of mica, which can be fitted to the edge of the cork. 

 Seedlings of bean, etc., can then be pinned to the cork in various 

 positions in the moist chamber thus constructed. The radicles 

 of the seedlings will be revolving and will therefore not grow 

 downwards. With this may be compared seedlings pinned in the 

 same positions to a cork fixed in a similar moist chamber, but 

 standing upright, not rotating. The radicles in this case grow 

 downwards. 



THE INFLUENCE OF MOISTURE. Although roots grow down- 

 wards in obedience to the stimulus of gravity, they are even more 

 strongly influenced by moisture. To try this, grow seeds in damp 

 sawdust in a box the bottom of which consists of wire gauze. 

 Then suspend the box in dry air, being careful to keep the saw- 

 dust moist. The radicles grow downwards through the saw- 

 dust, then they make their way through the wire gauze, and 

 finding themselves in dry air, curve and grow upwards again, 

 being attracted by the moisture in the sawdust. 



It should be remembered that although roots require moisture, 

 they do not thrive in stagnant water, for they need air as well as 

 moisture. Nearly all plants flourish better in drained, than in 

 undrained, land. Some of the advantages of drainage are, that 

 the roots can penetrate more deeply, and not only air, but also 

 water falling on the soil, can get into it. Moreover, this water 

 often contains nutrient materials derived either from the air 

 or from manure, which are thus supplied to the plant. Farming 

 in England has been considerably improved of late years by good 

 drainage. 



THE INFLUENCE OF LIGHT AND DARKNESS. Seeds grown in 

 moist air, instead of being kept in a dark cupboard until the roots 

 are fully grown, may be kept in the light. Then if one bottle is 

 covered with brown paper, whilst the other remains exposed 

 to the light, any difference in the growth of the radicle can be 

 seen by comparing the two. A still better plan is to grow the 



