NTLANDEB ON Till'. ALi;o-i.[iilKN HYPOTHESIS, &0. 147 



would then be there observed crammed with these elements. The 

 case, however, is far otherwise; for, on the contrary, such 

 stations arc avoided by Lichens, and are not inhabited, except 

 Bparingly by Collemacei ami a few others, which are not always 

 well developed ; nor do those which occur contain any para- 

 sites of that kind in their texture. Elsewhere I have adduced 

 that the gonidia and gonimia of Lichens constitute a normal 

 organic system necessary, and of the greatest physiological im- 

 portance, so that around them we behold the growing (or vege- 

 tative, if we may so term it) life chiefly promoted and active. a< 

 for example creating colorific matter. On the contrary, thofi I 

 portions of the thallus remote from the gonidia and more advanced 

 in age, as best appears in incrassate crustaceous lichens, having lost 

 their life, become entirely tartareous, forming, as it were, but 

 " thickened deposits." Thus the life is collected chiefly in the parts 

 around the gonidia (in the thin superficial stratum). Moreover the 

 lower, and but little gonidiose lichens, such as often occur amongst 

 the llielotrejnata, Graphides, Vetrucarice, Mijcopora, have but a 

 shorter life, and consequently are frequently found with the apo- 

 thecia either not rightly developed, or dead, and thus in this respect 

 manifesting an analogy with and verging towards the fungi. It 

 would be most inconsistent to admit that parasitic plants dis- 

 charge the function of organs within the plant which they invade. 

 Other and additional arguments against the parasitic hypothesis of 

 Schwendener may be seen in Caspary, " Ueber, dieneuren Ansich- 

 ten in Betreff der Flechten, monach diese Schmarotzer seieu in 

 Schriften der physik. okon. Gesellschaft in Konisberg, 1872, 

 Abth. ii., p. 18." I add nothing here concerning the hymeneal 

 gonidimia, which, without any "hyphae," and the hyphre of fungi 

 have certainly nothing common in structure with the " hyph®" of 

 lichens *, normally occupy the pyrenocarpous thalamia, which are 

 destitute of paraphyses, between the thecte of many species, and 

 nothing of the Friesiads or the gonimia of cephalodia, which simi- 

 larly constitute normal organs, and afford constant characters of 

 different species (not only in Stereocaulon and Pilophoron, but also 

 in Peltidea, Placopsis, Lecidea panceo/a, &c). It certainly seems 

 superfluous to delay longer in refuting an hypothesis of that kind. 

 But even though the gonidia of lichens should show an analogy 

 with the gonidia of " xYlgai" (and what is clearly known of the full 

 development or fructification of those algae treated of?), this cir- 

 cumstance would present nothing marvellous, and certainly would 

 not confirm any subversive theories. But it is not to be overlooked, 

 that under the name of Algae are received by authors plants wholly 

 ambiguous in their nature, and such, indeed, as are very near to 



* Here the author ad>ls in my copy — " The anatomical filamentose elements 

 of lichens are distinguished by various characters from the hyphae of fungi. They 

 are firmer, elastic, and at ouce present themselves in the texture of lichens. On 

 the other hand the hjpha3 of fungi are very soft, they possess a thin wall, and are 

 not at all gelatinous, while they are immediately dissolved by the application of 

 hydrate of potash, <fcc." 



