2o8 
P. Cavers. 
in Umbraculum. The midrib is traversed by an axial strand of pitted 
cells, and Tansley (68) showed that in B. Lyellii eosin solution passes 
along this strand more rapidly than through the surrounding tissue 
Fig. 33. Morckia flotowiana. I, Transverse section through base of plant. 
II, Similar section taken further forwards, st., conducting strands of midrib; 
m., mycorhizal zone ; rh ., rhizoids ; lam., lamina or wing of thallus; mid., 
midrib. x25. 
Fig. 34. Morckia flotowiana. Part of Fig. 33, II, x 70. 
of the midrib, so that we have here a rudimentary conducting strand. 
The antheridia are borne in two rows along the midrib on the upper 
side of the thallus, each antheridium being spherical, shortly-stalked, 
