CHLOROPHYLL GRANULES. 



41 



Chloroplastids, or chlorophyll granules, also called chloroleu- 

 cites ; (2) those which have some color other than green, — 



Chromoplastids, or chromoleucites ; (3) those which are devoid 

 of color, — Leucoplastids, or leucites. 



169. Chlorophyll Granides^ 

 or Chloroplastids, are met with 

 in the green parts of all plants ; 

 in fact, to them the green color 

 is due. But they are some- 

 times masked by the presence 

 of color in the cell-sap. Their 

 shape is spherical or spheroidal, 

 and somewhat flattened. They 

 have an average diameter of 2 to 

 5 fj., but many granules are con- 

 siderably larger than this. It 

 frequently happens that they be- 

 come of great size, owing to the 

 presence of solid contents, — for 

 instance, starch, — which may 

 accumulate in large amount. 



170. If the granules are sub- 

 jected to the action of alcohol, 

 their coloring matter is wholly 

 removed ; but the}' retain their 

 former volume and shape, ap- 

 pearing faintl}- outlined in the 

 protoplasmic mass in which 

 they are imbedded. Hence it 

 is proper to distinguish be- 

 tween the chlorophj-ll body of 

 the chloroplastid and the chloro- 

 phyll pigment which imparts to 7 

 it its characteristic color. 



The chloropluU bod}- may be sliown, b}' the process described 

 in 61, to be somewhat spongy in structure, and to have on its 



each other at the outset, become chloi'oplastids, chromoplastids, or leucoplas- 

 tids, according to the part which each is to play. Moreover, one kind of 

 granule can, under certain conditions, perform work which properly belongs to 

 another, and hence it is not always easy to identify the different kinds. In 

 most cases, however, their discrimination is very simple. 

 They are also called, collectively, Cbromatopbores. 



Fio. 7. Chloropliyll granules in tbe leaf of Vallisneria spiralis. ^5=. (Weiss.) 



