4^ British Fiinori. 



fungal portion absorbs the required mineral substances 

 from the substratum. Schwendener was the first to 

 indicate the true nature of lichens." Bornet followed ^ 

 by showing that in numerous instances the so-called 

 gonidia or algal portion of lichens could with certainty 

 be referred to known species of algie, and further 

 succeeded in producing a lichen synthetically by 

 sowing the spores of Parmelia parietina with Proto- 

 coccus. Quite recently Bonnier has published ^ the 

 results of investigations extending over several years 

 on the nature of lichens, and gives a long list of 

 species that he has produced artificially, by sowing 

 the spores of lichens with species of algge corresponding 

 to those met with in the same species of lichens grow- 

 ing naturally. Various methods of culture were 

 adopted, the details of which are given in detail, and 

 the article teems with additional proofs and corrobo- 

 rations of the correctness of vSchwendener^s views 

 concerning the nature of lichens. The same author 

 has also shown ^ that the spores of lichens germinate 

 readily on the protonema of mosses, but in this case 

 mutualism is not manifested, consequently we have no 

 perfect lichens having for their chlorophyllose element 

 the protonema of mosses. It is difficult to conceive 

 that lichens originated as we now understand them, 

 and from analogy, it is probable that in the first in- 



" Untersuchungen liber den Flechtenthallus, in Xageli's Brete. 

 zuv Wissensch. Bot., 1860. 



' Eecherches sur les Gonidies des Lichens, Ann. Sci. Xat. (Bot.), 

 vol. xvii., 1873. 



^ Eecherches sur la sjuthese des Lichens, Ann. Sci. Nat., ser. 

 vii., vol. ix. pp. 1-34, 1889. 



^ Germination des spores de lichens sur les protonemas des 

 mousses. Rev. generale de Bot., vol. i., p. 165, t. 1, 1889. 



