128 COLLEGE BOTANY 



length, mark one or more with India ink (using a fine pen or brush or 

 thread) into sections of about one-sixteenth of an inch. Wrap the seed in 

 wet cotton and insert the root into the tube of a glass funnel. Cover the 

 funnel with a plate of glass to prevent evaporation and set in a dark 

 place. Examine from time to time and determine region of greatest growth. 



Exercise 3. Seal the micropyles of a few lima beans with a quick- 

 drying varnish. Germinate in wet moss with untreated seeds. Compare 

 time required for germination of seeds in which the micropyles were 

 not sealed. 



Exercise |. Examine the seed of a castor roil plant and compare with 

 the bean. Note the caruncle. Remove the seed coats and note the stored 

 food. Examine the cotyledons and other parts of the embryo and compare 

 with the bean. 



Exercise' 5. Examine a grain of corn and compare with the bean and 

 seed of castor'oil plant. Note the groove with the embryo lying just below 

 the coverings. Remove the embryo from one grain; cut another grain 

 longitudinally. Note the plumule, radicle, hypocotyl, scutellum (cotyle- 

 don) and relation of embryo to the stored food. 



Exercise 6. Scrape the ovary and seed coats from one side of a few 

 grains of corn. Germinate with uninjured grains. Compare time of 

 germ:ination. Explain. 



Exercise 7. Germinate beans, seeds of castor-oil plant and corn in loam 

 soil and compare germination and growth. 



Exercise 8. Examine and germinate seeds of as many other plants as 

 may appear desirable, 



