GERMINATION OF BEANS 87 



plant be dug up, the cotyledons will be found to 

 have remained under the ground. Observe care- 

 fully at what point the roots start out from the 

 seed. 



111. There are, then, two types of germination 

 as respects the position of the cotyledons. In one 

 type, the seed-leaves rise above ground, or the 

 germination is epigeal ("above the earth"); in the 

 other, they remain where the seed was planted, or 

 the germination is hypogeal ("below the earth"). 



Ilia. The pupil should make a careful comparison of the dif- 

 ferences in germination between the two types of beans mentioned 

 above. He may profitably add a third factor to the experiment 

 by including the garden pea. If he has access to oak trees, he 

 may watch the germination of the acorns as they lie upon the 

 ground in very early spring. Examine horse-chestnuts. 



112. Measure the beans before they are planted, 

 taking the length, width and thickness. If delicate 

 balances or scales are at hand, it may be well to 

 weigh them, also. Then observe the increase in 

 size of the beans. Is this swelling associated 

 with heat or moisture, or both? The pupil can 

 answer this question by planting some seeds in 

 dry, warm earth and others in moist, cool earth 

 (which is kept little above freezing), and by 

 otherwise varying the experiment. Do dead seeds 

 those which are veiy old or which have been 

 baked swell when planted? The pupil will find 



