68 



BOTANY 



may be planted from five to ten times their own depth. Keep ths tem- 

 perature as near 75° Fahrenheit as possible. Protect at night from sudden 

 drops in temperature by careful covering of the young plants. Water 

 regularly and moderately. If the material for class work is ready at cer- 

 tain stages before time to use in the laboratory, the specimens may be placed 

 in 4 per cent formol solution until needed. After the different plants have 

 appeared above ground a daily record should be made of at least one of 

 each kind of seed or grain planted. ]Note the length of time it took each 

 to appear above the ground and make daily drawings until the young plants 



Sprouting beans. Note the arch in the hypocotyl. 



in its growth ? 



How is this of ';^e to the plan* 



are at least two weeks old. At the end of that time an entire plant of bean, 

 pea, and corn should be removed and drawn. You will thus accurately 

 determine the fate of each part of the growing plant. 



Answer the following questions from bean seedlings grown at home or from 

 material supplied you in the laboratory. Which part of the embryo breaks 

 through the seed coats first and at what point does it appear ? In what 

 direction does the hypocotyl grow? Does it always take this direction? 

 How does the seedling break through the ground? Which part appears 

 first above ground? Why does it assume this position? Are the cotyle- 

 dons pushed or pulled out of the ground ? What color has the plant above 

 ground? What becomes of the cotyledons in old specimens? Pleasure the 

 cotyledons in a young specimen and then again when the plant has grown 

 older. Do they grow in size? Make a table which shows the ultimate fate 

 in a bean seedhng of the following parts- cotyledons, hypocotyl, epicotyl. 



