38 



Tentamen Ptcridographiae (1836) in which he recognized 116 

 genera in the Polypodiaceae and Cyatheaceae. This was fol- 

 lowed in 1843 by his Hynienophyllaccae and in 1845 by his Sup- 

 pieincntiDn Tentaminis Pteridographiae , which treated the remain- 

 ing families. In the former work many new species were de- 

 >cribed and the Supplei)icntum was a monograph of the families 

 Ophioglossaceae, Marattiaceae, Osmundaceae, and Schizaeaceae. 

 His later works were Die Gefdsslnindc/ ini Stipes der Farr// (1842) 

 and Epimeliae Botanicae (1849), '" which, besides describing 

 many new species, he established 68 additional genera, bringing 

 the total number recognized by him to 232. Pres! was among 

 the first to recognize the distribution of the fibro-vascular system 

 both in the stem and in the leaf as having primary importance in 

 the matter of relationship among ferns, and after Robert Brown, 

 was the first really to look upon a genus of ferns as a natural 

 group of closely allied organisms, instead of a loose assemblage 

 of organisms whose superficial and accidental characters brought 

 them under a cut and dried definition based on artificial 

 resemblances. 



Such unnatural and unholy alliances as the groups of species 

 still included in Gymnograuuiie, AcrosticJiuvi, Polypodimn, and 

 Davallia in the Synopsis Filicuiii of Hooker and Baker, were 

 separated by Prcsl into much more natural groups, and while he 

 made errors, as might be expected in a pioneer, his system is in 

 many respects the most logical single system that has yet 

 appeared. 



Presl's collection of ferns is in the botanical museum of the 

 rierman University of Prague, although some of his t)'pes are at 

 Vienna. The collection lies in its original sheets, dust-covered, 

 unmounted, and unmolested. When we visited the collection in 

 1903 it was even impossible to consult any of Presl's voluminous 

 writings on ferns in connection with his collection, for the simple 

 reason that the extensive botanical laboratory in Prague did not 

 possess them. With the single exception of a solitary note by 

 Al. Braun there was little to show that any one else had ever con- 

 sulted the collection since Presl's death, and yet the collection, 

 next to those at Kew, Berlin, and Paris, is probably the inost im- 



