34 roLvroDiuM californicum. — californian polypody. 



from its rocky brow." We are very glad to be able to give a 

 representation of this very beautiful fern, because in pursuance of 

 our plan to take representatives of the Flora from every part of 

 the United States we want to have Oregon represented ; and also 

 because this species offers the opportunity to say a little on the 

 importance of examining the veins in determining the various 

 kinds of ferns. The earlier botanists paid attention chiefly to 

 the form of the fruit dots, their posidon on the fronds, or their 

 situation on the veins ; but characters derived from the veins 

 themselves do not appear to have attracted much attention till 

 a comparatively modern date. In 1836 Professor C. B. Presl, 

 one of two brothers both celebrated botanists of Prague, pub- 

 lished a work on ferns in which characters drawn from the 

 veins occupied a very prominent position. Those who make 

 ferns a special study do not seem to agree in all cases with 

 Professor Presl as to the precise value of such characters, but 

 still they are found generally to be of as much value as most 

 other characters in ferns, and hence all students in these times 

 examine the veins as closely as any other parts of a fern. Some 

 veins are simple, others branched, others run completely to the 

 margin, while others stop short. Again there are others which 

 continually diverge, and no matter what may be their length 

 never touch another after having once started from the parent 

 vein ; while there are others which seem to run backwards and 

 forwards, connecting one with another, and forming a complete 

 net-work all over the surface. In some cases these characters 

 are constant, that is to say, are generally found the same in all 

 the specimens of the species we may find, and then they form 

 what botanists call a valuable character; but in other cases they 

 are found to vary, sometimes having perhaps free veins, that is 

 never being connected at their points, and at others they form a 

 net-work, or as it is technically said, they anastomose. 



Our present species is just one of these uncertain cases. It 

 will be noted that the description translated from Kaulfuss says 

 "veinlets anastomosino-," but these will not be found in that 



