XIII 



LYCOPODINE^ 



505 



which the bud was originally produced. The young plant 

 arising from the gemma is at first composed of uniform paren- 

 chyma, but in the later formed portions a simple vascular bundle 

 is finally developed. No definite apical cell can be detected in 



Fig. 291. — Part of a vigorous plant oi -^Psilotum triquetrum, about J^ ; u, u, Sub- 

 terranean shoots; a, a, the bases of aerial branches; sy, synangia; B, branch with 

 two mature synangia, slightly enlarged; C, a single opened synangium, showing 

 the two lobes of the sporophyll below it (after Bertrand). 



the earlier stages, but later each branch of the rhizome shows 

 a pyramidal initial cell, much like that in the Ferns, but less 

 regular in its divisions, and it is not possible to trace back all 

 the tissues with certainty to this single cell. The branching is 

 a true dichotomy, but is not brought about by the division of 



