Of 



^/^ 



I 



J 



APPENDIX n. 



Ixvii 



periods of drought. This consists in the formation of the 

 so-called 'peculiar fruit' of the ProtonemecE, which may be 

 produced on any part of the plant, under the form of a 

 brownish ovoid mass made up of four or more cells. These 



are supposed to be 



* restino; 



gemmae/ the production of 



=*5 



^''aments are 

 when those 

 step in the 



'On 



post! i 



many modes of 

 laments, 

 ■ving manner :- 

 inch is 



4 



which is probably ' one of the means by which the life of 

 the plant is preserved during severe trials of drought and 

 cold/ Each one of them seems to be a sort of compound 

 gonidium, and from any one or more of its' constituent cells 

 confervoid filaments may ultimately sprout. 



3. 'But this is not the only method by which the con- 

 fervoid filaments are reproduced: any one of "the cells de- 

 tached from the other is capable of continuing the growth 

 of the filament in the same manner as each is capable of 

 doing whilst forming part of the filament, by branching and 

 division, as I have before noticed. And there is a great 

 tendency for these cells to separate from each other, more 

 particularly in the older filaments ; but whether old or young 



rablv in size, fe J they may bulge out on any side, and form a branch which, 



segmenting, becomes a true filament.' The separated cells 

 mentioned, in ail may be somewhat .elongated, though more frequently they 



:hes are delicate anrj are spherical, having dropped off from the ends of the fila- 



i been formed in li 



ee 



re 



or four' 



\ 



un-in? in towrf-'*' ] ^ents where three or four others have assumed nearly the 



The green contents of these separated globular 



iatio" 



^ of smaller 

 the former ro^r, » 



; From 

 of the cells, 



different' 

 ,s shown to b^ '" 



same form 



cells, or gonidia, may be granular 



or homogeneous, and 



they may or may not contain a central nucleus, as is ob- 

 served in the gonidia of Lichens. Others become more or 

 ess altered in form and appearance, and exactly resemble 

 some of the supposed independent forms of Conferva de- 

 scribed by the older algologists— e. g. C. mulHcapsularis and 

 <^- nnhrosa. Under the influence of warmth and moisture 

 these globular or elongated cells (a) give rise to filaments ; 



These cells also assume a deeper and brighter green colour 



-*■ 



e 2 



