6 GUIDE TO THE STUDY OP LICHENS. 



ignated lichens as ^^ rustici pauperrimi,'' which might 

 well be translated as " the poor trash " of vegetation. 

 This lack of interest in the lower organisms was quite 

 universal and explains why lichens were neglected, 

 particularly the really insignificant crustose forms. 

 As the result of the combined efforts of the various 

 lichenographers some 500 species or forms of lichens 

 were known at the close of the eighteenth century. 



The first investigator who made an attempt to study 

 the morphology and physiology of lichens was J. 

 Hedwig (1784). Though his conclusions were in the 

 main wrong, yet his investigations served as a stimulus 

 and an inducement to further study. This author, 

 was the first to make a special study of the sperma- 

 gonia. He also studied the spores and soredia. 

 He believed that the spermagonia were the first to 

 develop and that the apothecia and soredia developed 

 upon these subsequently. Furthermore, the sper- 

 magonia were looked upon as the male reproductive 

 organs, the soredia as the fertilizing elements and 

 the apothecia with the spores as the female organs. 

 A. P. De Candolle (1798) made some interest- 

 ing experiments as to the manner in which the 

 different lichens take up their food-supply. During 

 the same year Acharius, who is often spoken of 

 as the " father of lichenology," issued his " Prod. 

 Lich. Suec," in which he expressed great uncertainty 

 in regard to the manner of fertilization and the nature 

 of the reproductive organs. He even questioned 

 whether lichens were plants and expressed a desire to 

 classify them as polyps. Georgi (1779) made the 



