5^« 



SECONDAR}' CHANGES. 



e. g. Quercus. Corylus, Carpinus, Pyrus, Juglans regia, Sambucus nigra ^ Daphne 

 Mezereum, Rhamnus Frangula, Simaruba ofidcinalis ^, Ulmus •', Glycine sinensis. 

 Quillaja, Olea europcea, and Populus pyramidalis. In these cases the fibres of each 

 group are seldom radially arranged ; their arrangement as seen in cross-section is 

 usually irregular. 



(t) The bast of numerous other Dicotyledons contains fibres scattered through- 

 out the soft bast, singly or in small groups, as seen in cross-section ; traced 







nr 



I'lG. 214.— Sparinannia Africana; branch, transverse section (80). Below A— A is wood; above A— A is first 

 the cambial zone, then higher up and towards the outside is the layer of bast, the outer limit of which lies at *; 

 m larger medullary rays; the single radial rows marked X X are the smaller ones. Alternating with the 

 medullar}' rays are narrow strands of bast, consisting of alternate groups of fibres and of soft bast with narrow 

 cavities- On the external boundary of the bast are sacs or cells with stellate cr>stals. e remains of the epidennis; 

 p periderm; s remains of a sac containing mucilage, after the mucilage has been washed out. 



longitudinally they are also isolated, or form narrow strands, anastomosing with 

 others at an acute angle; sometimes they are distributed over the tranverse 

 section in large numbers, as in the external zone of bast of Ladenbergia magnifolia, 

 and in the bast of most Cinchonas S also in Ficus elastica, Morus, and Celtis%- 



* Von Mohl, /.c. p. 879. 

 - Harlig, /. r, p, 466. 



== Berg, Atlas, Taf. 28, &c. 



* Compare Berg, Atlas, Taf. 29-35. 



Ilartig, Forstl. Ciilturpfl. p. 450. 



