Chapter VIII 



73 _ The Chondriome (cont'd) 



duction of chlorophyll. In these cells, the chondriome always keeps 

 the characteristics which it shows in the meristem. It, therefore, 

 remains undifferentiated, made up of a mixture of mitochondria 

 and thin chondrioconts. 



These phenomena may be verified in fresh material by studymg 



Fig. 36. — Development of the two categories of chondriosomes in 

 the bud of Elodea canadensis. 1, diagram of longitudinal section of 

 bud; 2, mitochondria and chondrioconts in a foliar primordium at 

 level (A); 3, 4, chondrioconts transforming into chloroplasts in a 

 slightly older foliar primordium; 5, mature chloroplasts in cells of a 

 nearly mature leaf taken at (B). Some of the mitochondria have be- 

 come rods or chondrioconts; 6-11, details showing the same sequence of 

 events. C, level at which chloroplasts develop in the stem, also chon- 

 driosomes in Fig. 11. Regaud's method. 



the living bud. The tip of the bud may be seen, without any al- 

 teration taking place within its cells, by stripping it of its oldest 

 leaves and putting it in water under a cover slip which is pressed 

 gently so as not to injure the vegetative point. It is seen that the 

 meristem of the stem and of the youngest foliar primordia do not 

 contain chlorophyll. In addition to a large nucleus, these cells 

 show only a confusedly granular cytoplasm in which it is possible 



