THE HISTORY OF LICHENOLOGY. 9 



ology of lichens. It must, of course, be cmpliasized 

 that this was heretofore practically impossible owing 

 to the imperfections of the microscope. The com- 

 pound microscope was introduced at the beginning of 

 the nineteenth century, but, like all innovations, was 

 comparatively imperfect and was looked upon with 

 disfavor by many scientists who should have known 

 better ; some even going so far as to openly assert 

 that the compound microscoj)e would never excel the 

 most perfect simple lenses. 



The impetus to the scientific study of lichens was 

 given by two German scientists, Wallroth and Meyer, 

 who, peculiarly enough, began their work independently 

 but covered much the same ground and published their 

 results in the same year (1825). Both made a special 

 study of the morphology, growth and metamorphosis 

 of the lichen-thallus. Wallroth's style is very in- 

 volved. Each sentence contains a long series of 

 parenthetical clauses often occupying nearly an octavo 

 page. His terminology is also peculiar and requires a 

 special study. On one question the two eminent 

 writers were diametrically opposed ; while Meyer 

 believed in the spontaneous generation of lichens, 

 Wallroth did not, it being his opinion that they de- 

 veloped from gonidia and spores as well as by vegeta- 

 tive propagation. Wallroth gave a very detailed de- 

 scription of the structure and function of the gonidia, 

 soredia and apothecia as well as of the tliallus. Al- 

 though this author did most excellent work there is no 

 evidence to show that he made use of the compound 

 microscope ; in some instances he did not even use the 



