16 



BOTANY. 



a, section with carmine the protoplasm in the starch-bearing cells 

 may be made evident. 



(c) Study the starch of wheat, rice, 

 Indian corn, oats, etc. 



(d) Mount carefully a few threads of 

 Pond Scum (Spirogyra) which have been 

 for some hours in the sunlight. Note 

 the aggregations of minute starch-grains 

 in the spiral chloroplasts (Fig. 11). 

 Now add iodine and observe the color- 

 ation of starch-grains. 



(e) Make thin sections of leaves which 

 have been in the light for some hours, 

 and observe minute starch-grains in 

 the chlorophyll-bodies. Use iodine as 

 above. 



(/) Make longitudinal sections of 

 ripened apple-twigs and note the starch 

 stored in certain cells of the pith for 

 use when growth is resumed. 



24. Aleurone. — In mature seeds 

 there are commonly to be found 

 small rounded granules of albumi- 

 nous matter to which the name 

 of Aleurone has been given (Fig. 

 9). It is, in part at least, the 

 Ftq. 11.— Two plants of Pond protein matter of the older botan- 



Soum ( Spirogyra), showing spi- 

 ral chloroplasts, each with ag- jgts. It IS also identical with what 



gregations of starcn. At a and 



trch^f/eplrltSrftoTni^ l^^s been called the gluten of the 



ing. Magnified 500 times. ^^^^^^ ^j ^^^^^^^ ^^^^ ^^^^ ^^^_ 



25. Aleurone is poorly understood, but it appears to be 

 a dry resting state of protoplasm. Some, if not all, of it 

 may become active again upon the access of water and the 

 proper temperature. Possibly some of it serves as food 

 for protoplasm in the germination of seeds. 



Practical Studies. — (a) Mount in alcohol or glycerine a thin slice 

 of a ripe pea. Note the small granules (along with large starch- 



