THE HISTORY OF LICHENOLOGY. 5 



though some considered them as " mosses " or " fun- 

 goid " mosses. Micheli proceeded to arrange all the 

 known species or forms into thirty-eight orders based 

 upon the general macroscopical characters and the con- 

 sistency of the thallus. He illustrated the orders and 

 also studied the apothecia and the spores. Twelve years 

 later John Dillen issued his noteworthy " Historia Mus- 

 corum," in which the lichens are classified as mosses. 

 His work is well illustrated, and in many respects the 

 system of classification is superior to that of Micheli. 



After the above botanists others exercised their 

 ingenuity in establishing systems of lichens. Some 

 authors classified them with mosses, while others 

 placed them with fungi. The various groups were 

 quite universally based upon the external appearance 

 and nature of the thallus. Linne, " the immortal 

 Swede" (1753), combined all lichens in one group in 

 agreement with Tournefort. He, however, established 

 sub-groups based upon the characters of the thallus 

 as well as upon those of the apothecia. 



It will be remembered that at first there was a ten- 

 dency to classify lichens as a distinct group of plants ; 

 later to consider them as mosses or even as funafi. 



o 



This doubt and uncertainty continued to grow until 

 the close of the seventeenth century, when the confu- 

 sion reached its highest point. They were not only 

 classed as mosses and fungi, but also as algae, sponges, 

 liverworts, etc. This difference of opinions was due 

 to the fact that the knowledge of the lower plants, of 

 lichens in particular, was very imperfect. Linne, who 

 never pretended to be a friend of the cryptogams, des- 



