XXVUl PROCEEDINGS OF THE 



or spores. Here, however, we have the supposed parasite surround- 

 ing and enclosing its presumed victim, cutting it off from all com- 

 munication with the outer world from which it has to derive its 

 nutriment ; and yet we are to believe that the poor prisoner not 

 only sustains its own life and feeds its host, but flourishes, grows, 

 and multipHes. If the lichen feeds upon the enclosed gonidia, what 

 do the gonidia feed upon ? If there reaUy is parasitism in the case, 

 which is very doubtful, might it not be compared to that of Nema- 

 todes ? and may not the gonidia be the parasites, the lichen the 

 host ? or may not the gonidia be mere stages of existence of certain 

 lichens falsely ascribed to Algae ? The whole question is a very 

 curious one ; and the facts ascertained do great credit to the skill 

 and acuteness of Schwendener and others ; but they require much 

 more observation and study before the conclusions derived from them 

 can be taught as an established theory*. And whatever be the 

 result, the group of lichens is so distinct in its vegetative characters, 

 and at the same time so extensive and varied a one, that it seems 

 more methodical to treat it, as heretofore, as a distinct class, than to 

 absorb it in that of fungi, notwithstanding the close affinitj^ shown 

 by its reproductive organs. 



Sachs's Lehrbuch was above ten months printing ; and during that 

 time several important works bearing on some of the questions 

 treated of reached him, too late to be made use of. He has taken 

 care to refer to them in his Preface ; and stUl later a considerable 

 gap in our knowledge of the reproductive system of the higher cryp- 

 togams has been partially filled up by the discovery of very young 

 plants of Lycojpodium annotinum, reported by J. Pankhauser in the 

 first pages of the * Botanische Zeitung ' for the present year. He 

 traced these young plants to an underground prothallium, of which 

 he found one still in a sufficiently perfect state to show a'ntheridia 

 and traces of the archegonia. It thus became evident that Lyco- 

 jpodia, long associated geuerically with Selaginella, and which, owing 

 to our ignorance of their germinating process, are still allowed to 

 remain next to that genus, are, in fact, much more nearly allied to 

 Ophioglossese. I am happy to observe that the Edinburgh Botanical 



* Since writing the above I learn from Professor Dyer that Mr. Archer of 

 Dublin lias gone through a series of very careful observations with relation to 

 this question, and has consigned the results, accompanied by a full history of the 

 different views entertained by the various physiologists who have written upon 

 it, in an article now printing for the forthcoming part of the ' Monthly Mi- 

 croscopical Journal.' 



