148 



The genus Trichomanes whose name Linnaeus transferred from 

 our little tufted spleen wort to the tropical filmies, included some 

 species of Hymenopliyllum and at least one Davallia. Marsilea 

 included Salvinia natans and Marsilea quadrifolia, now recognized 

 as types of two different families of the Salviniales, and Pilularia 

 and Isoetes were monotypic, each including the more common 

 species of northern Europe. 



It was perhaps natural for Lycopodium with narrow leaves to 

 have been associated with the leafy mosses under Musci, but it 

 was strange that the foliose hepatics with the single exception of 

 Porella should have been placed apart under Algae. The genus 

 Lycopodium of Species Plantarum contains twelve species still in- 

 cluded under the genus, together with Psilotum medumand eleven 

 species of Selaginella. 



It is highly improbable that Linnaeus knew many of the pterido- 

 phytes which he arranged in this work, save the few with which 

 he was familiar in northern Europe. By far the greater number 

 of his species were compiled from books and his only knowledge 

 came from the more or less accurate illustrations with which he 

 was familiar. 



The apparently undue proportion of tropical American species 

 was due to the early works of Plumier and Sloane, which had 

 been copied by Petiver and probably by Plukenet. Sir Hans 

 Sloane collected extensively in Jamaica toward the close of the 

 seventeenth century, and Charles Plumier collected in Santo Do- 

 mingo and Martinique at about the same time. The elaborate 

 folio works of these two early writers form the foundation of our 

 knowledge of West Indian botany, and while they were digested 

 by Linnaeus only in part, they furnished him the basis for his 

 species of West India ferns. Later writers have traced many 

 additional species to the same early sources that Linnaeus only 

 skimmed, but did not fathom or comprehend. 



Linnaeus' herbarium was probably made, at least in great part, 

 after the publication of the first edition of Species Plantarum, and 

 on that account is of comparatively little value for the determina- 

 tion of his types. It is preserved at London in the rooms of the 

 Linnaean Society. After the death of Linnaeus' son, the collection 



