LEUCOPLASTIDS. 



43 



general protoplasmic mass of the cells, being no longer l^acog- 

 nizable. Those, however, which have been changed no further 



than by loss of color, closely resemble another kind of granule ; 

 namely, leueoplastids. (For exceptions see Chapter X) . 



174. Leueoplastids. These are found in parts which are 

 normally devoid of chlorophyll, such as tubers, rhizomes, etc. 



They may be wholly colorless, or faintly tinged with yellow, and 

 hence are apt to escape detection. They may be considered as 

 the points around which starch accumulates when stored for tlie 

 future needs of the plant. Schimper,' who first accurately de- 

 scribed them in all their relations, terms them " starch genera- 

 tors ; " they are also known as amylogenic bodies, which of 

 course means the same thing. They are seen to the best advan- 



1 ScMmper: Bot. Zeit., 1880, 1881, 1883. 



Fig 9 &. Same, more advanced: a, tlie amylogenic bodies are covered with starch- 

 grains; 6, two nuclei on a cell-wall, each surrounded by amylogenic bodies covered by 

 starch. ';». (Schimpev.) 



Fig. 10. a. Young amylogenic bodies surrounding the nucleus of a cell in the root of 

 Phajus grandifolius; b, same, with starch-grahis developing; c, same, more advanced, 

 ej". (Schimper.) 



