EARLY NOTIONS ABOUT THE LOWER PLANTS 85 



The chief steps by which the morpholog-y of the 

 flowering plant has been attained are these : — Cesalpini 

 (1583), followed by several other early botanists, recog- 

 nised the fundamental identity of foliage-leaf, perianth- 

 leaf, and seed-leaf. Linnaeus (1759) added stamen and 

 carpel to the list, identifications of greater interest, but 

 only partially defensible. Wolff (1759) justified by 

 similarity of development the recognition of floral organs 

 as leaves. Goethe (1790) traced structural similarity, 

 transitions, and retrogression in leaves of diverse 

 function. Hofmeister (1849-57) showed a relationship 

 between the flowering plant and the higher cryptogams. 

 Oliver and Scott (1904), inheriting the results of 

 Williamson's work, discovered a carboniferous seed- 

 bearing plant, one of a large group intermediate between 

 ferns and cycads. It is now possible to explain the 

 resemblance of the various leaf-like appendages of the 

 flowering plant by derivation either from the leaves or 

 the sporophylls (the latter not being wholly leaves) of 

 some extinct cryptogam, which was either a fern or a 

 near ally of the ferns. 



Early Notions about the Lower Plants. 

 The fathers of botany neglected everything else in 

 order to concentrate their attention upon the flowering 

 plants, from which very nearly all useful vegetable pro- 

 ducts were derived. The lack of adequate microscopes 

 rendered it almost impossible to investigate the structure 

 and life-history of ferns, mosses, fungi, and algae until 

 the nineteenth century. As late as the time of Linnaeus 

 it was possible to maintain that they developed spon- 

 taneously, though the great naturalist himself called 

 them Cryptogamia, thereby expressing his conviction 

 that they reproduce their kind like other plants, but in 



i 



