22 



HICKS, ON GONIDIA OF LICHENS. 



HASSALL. 

 Hcematococcus vulgaris. 



}} 



microsporus. 

 minutissimus. 

 Coccochloris protuberans. 



variabilis. 



muscicola. 



Jiyalina. 



depressa. 



rivularis. 



Ch^evillii. 



obscura. 



Brcbissonii ? 

 Sorospora virescens. 



KIJTZING. 



Gleocapsa vulgaris {Chloro- 

 coccus vulgare, 

 Greville) . 

 „ montana. 



„ confluens. 



Palmoglcea. 



Microhaloa. 



And if we regard those similar forms of a red colour as 

 merely a ivinter condition of those of green colour^ which is 

 now pretty well certain^ then we must add to the above list, 

 probably, Palmella cruenta, Hassall ; Hcematococcus insignis 

 and sanguineus, Hassall ; and some forms of Protococcus 

 nivalis, Hassall. 



It is very possible that, as observations extend, other lichen- 

 gonidia may be found, yielding explanations of the life-history 

 of many kindred forms. At the same time, because we 

 have shown that the lichen- gonidium can produce Gleocapsa, 

 Palmoglcea, &c., it is not hence, by any means, intended 

 to be asserted that such is their sole origin ; on the contrary, 

 there can be little doubt but that other vegetable growths 

 are, during certain vegetating processes, capable of giving 

 rise to very similar cells. In either case, it seems we can 

 no longer assign them that position they have hitherto held 

 as separate existences ; but they must fall before the extended 

 study of the life-history of plants into the rank of but one of 

 the many alternations which, it becomes more evident every 

 day, many families of the vegetable kingdom periodically 

 pass through. 



The relation of the lichen-gonidium to Nostoc and its 

 allies will form the basis of Fasciculus III. 



X 



