841 



** Fronds pinnate (or, when young, simple). 



f Costa central. Sori on both margins of 



the nearly equal pinnae, 

 ff Costa excentric marginal or obsolete. 

 Sori on the superior margin of the 

 unequal pinnae. 

 *** Fronds bipinnate or decompound. 



[Genus] 2. — Dictyoxypbium. 



The author appears to congratulate himself on having, by means of 

 the tribes, subtribes, genera and subgenera, sections, asterisks, dag- 

 gers, parentheses, &c., avoided the errors of " Dr. Presl and Mr. John 

 Smith, who," he declares, " have showed themselves peculiarly ad- 

 dicted to multiplying genera, have not always taken Nature for their 

 guide, nor succeeded in eliciting a simple and tangible arrange- 

 ment." We are therefore compelled to believe that the author 

 considers the foregoing " a simple and tangible arrangement," and 

 that starred and daggered sections, founded on the characters of 

 " pinnatedly " or " pinnatifidly divided," " pinnae more than an inch 

 long, " " pinnae less than an inch long," and similar distinctions, are 

 really to supersede the elaborately described characters of fructifica- 

 tion and venation given by the authors above mentioned ; for he 

 expressly says at p. 144, that " the variations of form in the involucre 

 or indusium is more useful as aflfording specific, rather than generic 

 characters." Can Sir William Hooker be serious in this ? Is not his 

 object rather to apologize for not using the fructification in his mul- 

 titudinous divisions, than to enforce the superiority of a method long 

 since exploded, although carried out with considerable ingenuity by 

 Withering, and the botanists of his day ? Had Sir William taken 

 the third volume of Withering in his hand, and turned to the 

 genus Polypodium, divided exactly on the plan he now proposes, we 

 think he could not fail to have pencilled certain commentaries against 

 the species as they stand. We give Withering's synopsis in roman, 

 and the commentator's supposed pencillings in italics. 



"Genus Polypodium. 



" § I. Leaves wing-cleft. 



" P. vulgare." A Polypodium, W. J. H. 

 "§II. Leaves winged. 



" P. Lonchilis." A Polystichum, W. J. H. 



*' P. Ilvense." A Woodsia, W. J. H. 



" P. Cambricum.'' A Polypndiuw, var. only, W. J. If. 



