120 W. ARCHER. 



Collemapuljwstim after recent rain, when the thalhis is swollen 

 up by moisture, certain examples are to be met with which 

 are in a manner dimorphic — one portion has its normal form, 

 another much resembles Nostoc commune. The examination 

 of a thallus thus deformed shows that the difference of aspect 

 is due to the decay or local death of the hyphee. 



Professor Schwendener comes forward once more in 

 explanation and defence of his new theory in a communica- 

 tion made to the Natural History Society of Basel.^ This is, 

 however, hardly more than a recaj)itulation of his already 

 published views, put together at the request of the Society, 

 and it does not seem to contain any absolutely new matter. 

 After dwelling upon the parallelisms between l^ichens and 

 Fungi, he proceeds to review recent researches, from which 

 he holds that the old views as to lichen-gonidia are rendered 

 questionable ; whilst, on the one hand, the genetic con- 

 nection between the gonidia and the hyphse remains un- 

 proved, on the other, the agreement of the former with the 

 algfe is placed in a clear light. The more important points 

 which he proceeds to recapitulate are : — 



1. He reasserts that those hyphse which show a con- 

 nection with the gonidia do not prove that the latter 

 originate from them. The gradual development of the gonidia 

 by a swelling up of the end cell of a hypha has been observed 

 by no one. On the other hand, he has seen in certain gela- 

 tinous lichens that this union occurs by a growing-together 

 or " conjugation " of a hypha-branch with a fully-formed 

 gonidium. He has seen two and three stipites passing off 

 from the same thread in union with the cells of one connected 

 chain, which would not be possible if, like cherries or apples 

 to their pedicels, they stood to them in a genetic relation. 



2. He then dwells on the resemblance or identity of the 

 gonidia with certain Palmellace<2, Chroolepus, &c. (already 

 discussed in previous communications).^ 



3. These algee in the free state reproduce themselves by 

 zoospores. So it has been proved do the gonidia, but the 

 author repeats his objections to the interpretation of Famintzin 

 and Baranetsky. 



4. Some lichens possess a gonidia system with apical and 

 stem - cells — that is, with independent terminal growth 

 [Ephebe, Spilonema). 



The author then gives an epitomized resume of the " eight 



^ Schwendener, ' Die Flechten als Parasiten der Algen,' in Verhandl. der 

 Naturf. Gesellscliaft in Basel/ 1873, p. 527. 

 2 See ' Quart. Journ. Mic. So.,' vol. xiii. n. s., pp. 217 et seq. 



