Bozuer.—Studies in the Phytogeny of the Filicales. VIL 25 
which interpretation their time and place of origin would accord. The fact 
of their presence is, however, interesting in connexion with the view 
expressed by Mettenius, which will be discussed later. 1 
Paesia scabendct rarely, if ever, produces fertile leaves in this country. 
I am indebted to Dr. Cockayne, F.R.S., and other helpers in New Zealand, 
for material giving the essential features of its sorus. These correspond to 
what has been described for P. viscosa, excepting that the hairs are fre- 
A 
Fig, 22. A-c. Vertical sections of the sorus of Paesia viscosa. (x 75.) 
quently absent. The sorus is either continuous or interrupted, with a 
marginal commissure. Sections show that it is distinctly inclined to the 
lower surface. The upper indusium is well developed, but the lower has 
never been seen thicker than a single layer of cells, and it is closely 
applied to the lower surface of the leaf (Fig. 22 bis , a). It is also 
very inconstant in occurrence, and frequently altogether absent. The 
sporangia originate in basipetal succession, but the series is not long 
continued. Evidence of this is seen in sections approaching maturity ; but 
1 See Mettenius, Farngattungen, iii, p. 7. 
