n6 Morphology BOOK'I 



from the habit of their branching, were divided into the 

 Lycopodiaceae and the Ligulatae. The Lycopodiaceae 

 comprised the Lycopodieae, Psilotaceae, and Phyllo- 

 glosseae ; while the Ligulatae, so called from the develop- 

 ment of a ligule in connexion with their leaves, included 

 the Selaginelleae and Isoetes. 



Though Sachs included the Osmundaceae and Schizaea- 

 ceae in the Stipulatae he did not appear to be satisfied 

 with their position there, as he discussed them, in the 

 detailed examination of their structure, with the Filices 

 proper. The association of the Marattiaceae with the 

 Ophioglossaceae was based upon similarity of their steins 

 and roots, and the complexity of their sporangia. Further 

 knowledge of the life-history of the members of both 

 groups has shown their affinities to be hardly so close as 

 Sachs supposed. 



The very distinctive group of the Rhizocarpeae was 

 found to be possessed of characters so nearly resembling 

 the true Ferns that with the recognition that heterospory 

 alone did not form a sufficiently differentiating characteristic, 

 the desirability of keeping them as a separate group of 

 the Vascular Cryptogams, co-ordinate with the Ferns, was 

 no longer great, and like the Ophioglossaceae Sachs included 

 them in the more comprehensive group of the Filicineae. 



Sachs' classification stood the test of examination, and 

 its satisfactory character was, on the whole, emphasized by 

 the detailed anatomical researches which were carried 

 out by various observers during the later years of the 

 century. With certain modifications rendered necessary 

 by these and by the gradually accumulating evidence 

 derived from fossils it held its position till the end of the 

 period under review. 



In 1880-1 Goebel suggested a classification of vascular 

 plants on the lines of the character of the development 

 of their sporangia. The Ferns and Rhizocarps, in which 



