268 Noii-lsolablc Races. 



viouslv results in an insufficient assimilation of carljonic 

 acid gas. Thus the variegated parts grow less vigor- 

 ously and are less resistant than the corresponding green 

 ones. The Cy perns altcrnifolius of our greenhouses, the 

 Aspidistra elafior and a number of other favorite varie- 

 ties show this clearly. Arundo donax often attains a 

 height of three or more meters whereas its striped vari- 

 ety is scarcely half that height. Leaves of the variegated 

 Aspidistra very often have one of their longitudinal 

 halves green, but the other colorless. In such cases the 

 leaf is distorted owing to the insufficient growth of the 

 colorless half. The same thing happens in many other 

 cases. 



The yellow leaves and parts of leaves, however, are 

 not entirely without the green coloring matter, nor wholly 

 without the power of assimilation. Most of them give 

 a green extract when put into alcohol, and if examined 

 under the microscope patches of green tissue can be found 

 here and there, especially near the veins. The power to 

 sustain life, however, is often lacking and the leaves die 

 shortly after their growth is completed. Therefore, a 

 high degree of the anomaly is not in favor, because the 

 plants which possess it often become disfigured by the 

 edges of their leaves turning brown. Many plants in 

 which the variegation has gone too far die in their very 

 early stages, while others have not sufficient strength to 

 flower and bear seed. This latter circumstance is of 

 special interest because it follows that plants with a high 

 degree of variegation as a rule can have no part in the 

 propagation of the variety.-^ In the opinion of some 



^ It is perhaps scarcely necessary to state that these remarks do 

 not apply to brown and purple leaves or those with red spots. For 

 information on this point see Stahl's excellent article Uebcr bunte 

 Laubhldtter, Ann. Jard. Bot. Buitenzorj^., Vol. XTII, Ft. 2, 1896, p. 137. 



