APPENDIX D. Ixiii 



may be diverted into some other mode under the influence 

 of various conditions at present unknown to us. 



But is it possible that just as the algoid cycle of develop- 

 ment may merge into the higher Licheno-algoid cycle, so this 

 complex cycle may merge into one still higher, in which 

 the various forms of Mosses must be concluded ? From 

 what we already know, this is really not so utterly improbable 

 as it might at first appear. Much careful observation would 

 be required to establish such a possibility as a fact, but the 

 observations to which I will now call attention give a 

 certain warrant to the assumption. They afford indications, 

 at all events, which should be sufficient to make future 

 inquirers approach the subject with their eyes fully open to 

 the marvellous possibilities of change presented by the pri- 

 mordial forms of living matter. 



Gonidia are produced from almost any part of the thallus 

 of Lichens ; but although, in exceptional conditions, they 

 may also be produced from the most different parts of 

 Mosses, they are thrown off principally,, and as a rule, from the 

 so-called 'confervoid filaments' or 'confervoid radicles/ The 

 latter are generally to be observed, in more or less abundance, 

 springing more especially from the part where the ascending 

 axis joins the true roots of the moss. These filaments, 

 previous to the investigations of Kiitzing, were looked upon 

 as true Algae, and were described under the generic names 

 Protenema and Gongrosira. Kiitzing 1 , however, showed 

 that they were natural products of Mosses, and this view 

 of their nature was afterwards taken by Schimper 2 , who 

 traced more fully the development of the confervoid filaments 

 from the spore, and the origin of the leafy axis of the moss 

 from them. The investigations of Dr. Braxton Hicks have 



1 'Phycolog. Generalis,' and ' Linnsea,' Bd. viii. 1833. 



2 ' Recherch. sur les Mousses,' 1848. 



