138 W. ARCHER. 



reserve nutriment appeared to have been not yet wholly 

 used up from the spore. 



After a three-months'' culture (in 1873) I at last saw as 

 the result of the meeting of the filament and algae, in the 

 neighbourhood of the place of contact, there had originated a 

 very great number of branches of the filaments, of which the 

 greater number had attached themselves afresh to the surface 

 of one or more of the algse and had produced afresh lateral 

 branches. The nutriment from the spores was after this 

 period of culture wholly used up, so that the spores had 

 become hyaline. Certain cases of copiously branched hj phae 

 might readily give rise to the conjecture that the hypha-mass 

 must be supported from some other source besides the reserve 

 material from the spore ; this conjecture becomes indeed 

 fully confirmed by comparison with those spores which under 

 the very same circumstances have germinated for an equally 

 long time, but without the filaments having encountered 

 algae in their way. 



The results of my research may be thus briefly expressed : 



So soon as a germinating filament of a spore of a hetero- 

 merous lichen, or indeed one of its lateral branches, comes in 

 contact with an alga of the species which plays the part of 

 gonidia-former in the thallus of the lichen, it becomes 

 attached on the surface of the alga, growing thereupon to a 

 greater or less extent. The first result of the adhesion is 

 more intense growth and increase of the number of hypha- 

 branches, which partly in their turn again become attached 

 to algae, and also give off" lateral branches, so that ultimately 

 the alga or algal-colony which has come into contact with the 

 germinating filaments, becomes completely encompassed by 

 hyphae. 



Bornel's cultures, like mine of last year, were brought to 

 a standstill by intruding fungi. I may then indeed express 

 my opinion that the results obtained by me the previous year 

 and those published this summer by Bornet are equivalent. 

 Although the results of our cultures would lead us both to 

 infer the truth of Schwendener's theory for the heteromerous 

 lichens, they would not however be wholly decisive, because 

 our cultures did not last long enough to cause the whole 

 of the reserve material to have become used up from the spores. 

 I consider, however, as regards the nature of the organic indi- 

 viduality of the heteromerous lichens, the results obtained in 

 my three-months' culture at the beginning of this year as 

 decisive on the question, because not alone the C^stococcus- 

 cells were wholly involved by the branches of the germinating 

 filaments, but further the numerous ramifications of these last 



