119 



milar structures of Vhytocrene. The leaf -arrangement is also 

 spiral and , so far as could be judged from the specimens seen, 

 the angle of divergence of the leaves closely approximates ^/s; 

 but the actual relation between the bast-plates and leaves could 

 not be definitely determined from the material at hand. 



In the regions i^sx) lying tov^ard the centre of the stem from 

 the bast-plates, the remains of a parenchymatous tissue were 

 found, which thus agree perfectly in position with the areas 

 of soft-wood („Holzausfullung") in Phi/tocrene. In a similar man- 

 ner the traces of parenchymatous tissue {sb) were found roun- 

 ding the prominences of the wood and undoubtedly correspon- 

 ding with the soft-bast („Bastausfullung") of Phyiocrene. In 

 Fyrenacantha no distinct inner ring of secondary wood could 

 be found. The tissue of the region r, r appears to consist merely 

 of the primary vascular bundles and the peripheral cells of the 

 pith, which have undergone a considerable lignification. 



Strasburg, Nov. 1889. 



