i6 



GENUS PALLAVICINIA 



The growing point of the shoot lies at the bottom of a more or less 

 evident notch, formed by the active growth of the tissue on each side of 

 the apical cell. The latter has segments cut off only from its two lateral 

 faces. Seen in horizontal section (Fig. 8, C) it is a narrow triangle, with 



A 



Fig. 8. Pallavicina radiculosa. 



of 



A. Cross-section of the thallus apex, showing the apical cell, x, and the apex, 



a branch., a, a are the young scales subtending antheridia. 



B. The apex of the shoot, more highly magnified. 



C. Horizontal section of the shoot apex, showing the apical cell, x, and a very 



young antheridium. 



D. Vertical longitudinal section of the apex. 



E. Archegonial plant, x 3. 



