8 REPRESENTATIVE PLANTS 



lirst appearance of the sprouting h3q30cotyl ; (b) second 

 stage, the first appearance of the plumule ; (c) third stage, 

 the appearance of roots and foliage leaves. 



Detailed study. Study each seedling furnished, and deter- 

 mine what part of the seed first shows growth ; also from 

 what part of the seed coat it makes its exit. Study this 

 feature in sprouting seeds, placed on blotters between glass 

 plates, and observe direction of growth of the hypocotyl. In 

 the same way study the growing plumule, observing its 

 direction of growth. 



Carefully observe the cotyledons in the sprouting seeds 

 of various stages and determine any change of position, 

 form, or color assumed. Study, if possible, seeds of beans 

 and peas planted in earth, and observe the hypocotyl arch 

 in the one and its absence in the other, and the effect on 

 the cotyledons in each case. 



Drawings. Make drawings showing the several stages in 

 each seedling furnished for study. 



Other work. In the growth of the seedlings, what becomes 

 of the seed coats ? Study well this feature in as many seed- 

 lings as possible. What seems to be the purpose of the 

 cotyledons ? What agent do you think causes a change in 

 the color of the cotyledons ? What benefit to the seedling 

 may this change bring about? From the various experi- 

 ments made, what, in your judgment, are the necessary con- 

 ditions for the sprouting (renewal of growth) of the seeds ? 

 Look up the word " germination " and find out whether or 

 not it is a correct term to use for the sprouting of seeds. 

 What is the first change in the sprouting of a seed, that the 

 dry seed undergoes, and how is this brought about ? (Read 

 the osmosis experiment, under roots.) Try another simple 

 experiment, which consists in placing a few dried raisins in 

 water and observing the results, which are like those occur- 

 ring in the soaked seed. 



Experiments. At this stage in your study make the fol- 



