146 SYDNEY H. VINES. 



admits that these differences do not hold good in all cases. He 

 states as a fact that there are Lichens, for the most part crusta- 

 ceous, such as Secologia abstrusa, Hpnenelia affinis, Sarcogyne 

 prioigna and others, which have no h)'pha3 in their thallus, 

 although asci and paraphyses are present. Such a fact as this 

 he considers to be a crushing proof of the absurdity of Schwen- 

 dener's theory, for here are Lichens in which only one of the 

 usual constituents is present. 



In support of his second proposition he points out that 

 Baranetzky has observed the protrusion of hyphal filaments from 

 gonidia, and adds that he has himself seen this occur in Poro- 

 cyphus and Collema. Such an occurrence is quite unknown 

 among the true Algse. Furthermore, it is well known that 

 several forms of gonidia may occur in the same lichen-thallus, as 

 in Harpidiim rutilans, Fannaria granatina, Racoblenna trem- 

 nlaca, &c., and Korber suggests that it is extraordinary that a 

 Lichen should require so many forms of Algse to act as the 

 gonidia of its thallus. He concludes his argument by saying 

 that if the gonidia were true Algae they would by this time, 

 have been all met with in the free state, whereas this is by no 

 means the case; the gonidia of Nsetrocymbe, Phylliscum, 

 Melanormia and others, for instance, have not yet been found 

 elsewhere than in the lichen-thallus. Moreover, he insists that 

 when gonidia are found in the free state, they are not therefore 

 to be regarded as Algse. Finally, he lays stress upon the apparent 

 fact that the gonidia resemble only such so-called Algse as repro- 

 duce themselves solely by division. 



In supporting the third proposition, the author adopts the 

 view of Fries, according to which the term '^ parasitism" is inap- 

 plicable in describing the connection of the " fungus" with the 

 "alga" in a lichen-thallus, and adds that if any "parasitism" 

 exists at all it must be mutual, pointing out that in a thallus 

 there are so many gonidia which are not connected with hyphse 

 that the relation of the latter to the former must be other than 

 that of a parasite. 



In the concluding paragraphs he recalls, as Miiller also does 

 in his above-mentioned paper, the old view of the origin of the 

 gonidia from the hyphse, and goes on to say that if the connec- 

 tion of the gonidia with the hyphiB is not of a genetic nature, it 

 must indicate some nutritive process by which the gonidium 

 obtains from the hypha some of the material which is essential 

 to its existence. From this stand point he ventures upon some 

 remarkable speculations as to the probable details of tliis nutri- 

 tive process whicii need not be considered here. 



He enumerates linally the various modes in which a lichen- 

 thallus may be reproduced, six in all, of which two are by means 



