^38 SECONDARy CHANGES. 



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

 Mezereum, Rhamnus Frangula, Simaruba officinalis", Ulmus S Glycine sinensisj 

 Quillaja, Olea europsea, 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. 



■ {c) 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 



riG, 214. — Sparmannia Africana; branch, transverse section (80). Below A — A is wood; above A — ft is first 

 tile cambial zone, tlien 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 

 medullary 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 crystals. ^ remains of the epidermis; 

 / periderm ; .r 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'*, also in Ficus elastica, Morus, and Celtis'; 



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

 ' Harlig, /. c. p. 466. 



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

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

 Hartig, Forstl. Culturpfl. p. 450. 



