Chap, iii The Study of the Cryptogams 229 



sphere, and by the end of the century its botanical side 

 was of far less importance than its pathological relation- 

 ships. It was then rapidly spreading into the fields of 

 bio-chemistry, and normal as well as abnormal physiology. 

 Its pathological side, however, was developed almost exclu- 

 sively in relation to the animal kingdom. Very few cases 

 of bacterial infection of plants were known, so that a very 

 large field of inquiry was about to be opened up. The 

 range of study in this direction was, however, a matter 

 for the new century. 



Another feature of considerable interest was the appear- 

 ance of the new classification of the Fungi, put forward 

 by Brefeld and supported by many of the most eminent 

 botanists, particularly von Tafel, who adopted it in his 

 Vergleichende Morphologie der Pilze of 1892. Brefeld's work 

 extended over many years, his memoirs appearing from 

 1873 to the late eighties, and elucidating the life-history 

 of many forms. The classification differed fundamentally 

 from that of De Bary, for Brefeld held that the higher 

 Fungi are entirely asexual and have descended from the 

 Phycomycetes through the Zygomycetes ; while the Oomy- 

 cetes have given origin to no other group. De Bary on the 

 other hand considered that the Oomycetes were the ances- 

 tors of the higher forms, the line of descent leaving the 

 Zygomycetes on one side. Brefeld's views were to a large 

 extent disproved by Harper's work on the sexual fusions in 

 Sphaerotheca in 1895. Though received with considerable 

 favour, his classification did not replace that of De Bary. 



The discovery of the true nature of the thallus of the 

 Lichens was another contribution made to the knowledge 

 of the Fungi after i860. Its symbiotic character needs 

 nothing more than mention here, as it has been spoken 

 of more fully in a previous chapter. Certain anatomical 

 details remain to be described a little later. 



The investigations of the earlier times into the Fungi 



