INTERCELLULAR SUBSTANCES AND WALLS 



71 



group, but the product resembles gymnosperm rather than native 

 angiosperm lignin in all respects. 



Table 3. Experimental Lignin Formed From Eugenol in Test 



Species 



Species 



Lignin formed 

 Without With 



H 2 2 H 2 2 



Ultraviolet spectrum 

 of dioxane extract 



Ar 



Density max, 

 Density min. 



We know, however, that angiosperm lignins are more highly 

 methylated than their gymnosperm counterparts, a condition 

 which is explained by the presence of the syringyl— or pyrogallol 

 dimethyl ether— group in the former. Hence, the synthetic lignin 

 reflects in its properties the precursor rather than the tissue in 

 which it was formed. 



That tissue-specific factors tend to change the product formed 

 from a single precursor, however, is shown by the spectral prop- 



