BoT.— Vol. II.] NOTT—CALIFORNIAN NITOPHYLLA. I3 



are remarkable. Notwithstanding this fact, the variations 

 can be so expressed in terms of size, shape and position 

 that clear distinctions can be drawn between species. In 

 some cases the sporangia occur in narrow lines of varying 

 width arranged in a flabellate fashion on the upper divisions 

 of the frond, extending perhaps from its median portion to 

 the margin — their regular position in N. harveyamim and a 

 disposition frequently seen in N. ruprechtianum — perhaps 

 only found as a fringe just within the margin, as often 

 observed in N. 7'uprechtiamini. Other forms have the sori 

 in linear strips or patches along the margin of the frond, an 

 arrangement best seen in N. violaceum. In another spe- 

 cies, N. iniiltilohuni, the sori are irregular in shape, rounded 

 or linear-elliptical, with their longer dimensions extending 

 transversely across the frond upon whose upper segments 

 they are borne. The sori occur in other instances as 

 rounded or elliptical patches borne either singly upon distal 

 lobes, as in N. andersoniammi , or scattered irregularly over 

 the surface, as in N. spectabile, sometimes displaying a ten- 

 dency to arrange themselves into lines, as is well shown by 

 JV. fryeamim. In yet other plants the sori are minute, 

 rounded structures, densely aggregated between the anas- 

 tomosing nerves and veins of the frond, e. g., JV. latissimum. 

 Proliferation. — The capacity for proliferation possessed 

 by some species is very great. To such an extent does 

 this phenomenon take place, that specimens are often 

 found in which the primary frond has remained compara- 

 tively undivided, and has produced from its margin numer- 

 ous proliferations which exceed in size the primary frond 

 itself. The favorite point for the production of prolifera- 

 tions is along the margin of the frond, especially after this 

 has been weathered by the waves. In such cases the 

 original frond may be reduced to a narrow strip, which will 

 produce proliferations surpassing in size the original portion 

 of the plant. In some species, particularly in JV. rti-prechti- 

 anum, the frond becomes reduced to the midrib; this per- 

 sists for a longer or shorter period, and proliferates very 

 freely, so that by this process the plant practically becomes 



