FLORIDE.E. 



[ 327 ] 



FLORlDEiE. 



I\ed or colourless albuiiiinous crj'stalloids 

 an' found in souie ot" the Floridt';u. 



Three kinds of reproductive structures 

 occur iu these plants, viz. : — 1, tcfra^porcs ; 

 2, uporca ; 3, spcrmatozoids or anfhcrozoids. 



The tt'tnispores or fefiru/onidia. These 

 structures are of similar organization 



They consist of an 



throughout the order 



Fig. 248. 



lihyiKUococcus eoronopifolius. 



Section of the frond with tetraspores. 



Magnified 200 diameters. 



oblong or globular external cell or sac (pen- 

 spvre), at tirst filled with gramUar contents, 



Fig. 249. 





Ptilota plumosa. 



Section of frond with tetraspores. 



Magnified 200 diameters. 



which contents subsequently separate into 

 four portions, called sporules, either by 

 three transverse fissures (fig. 248) ; by two 

 fissures at right angles, cutting them into 

 quarters like an orange ; or by tri-radiate 

 fissures which part them into the ' tetra- 

 hedral' group (fig. 249) so often found in 

 the division of spore- and pollen-cells : the 

 last two occur in the spherical tetraspores. 

 The tetraspores are rarely found collected in 

 any capsular structure ; but in the Corallines 



Fig. 2r)0. 



iiiiciaui'aiuMU(ia[ucLCci.o 

 comKituiecuauuuuuaaw 



Hildenbrant san- 



guinca. 

 Section of a concep- 



{[\g. 141), and in some few foreign genera, 

 they are grouped iu hol- 

 low cases (co/iccpfnch's, 

 fig. 250). In many in- 

 stances, however, they are 

 found in pod-like bodies 

 (sfichidia, ri. 4. iig. l.-5?>), 

 either formed by meta- 

 morphosis of portions of 

 the lobes or lobules of the 

 frond (Pl(icaniiu>n), or 

 arising independently on 

 it. In others the tetra- 

 spores are naked (Calli- 



tnammon), scattered over tacle containing tetra- 



the sides or fixed at the tips spores, 

 of the branches. In the -^=»g"- 5° d.ams. 

 majority of cases, however, these bodies are 

 immersed in the substance of the lobes or 

 lobules, not evident externally except by 

 the darker colour of the frond at the point 

 where they are collected ; a lens is then 

 required for their detection : they here 

 appear to be formed either of the cells of 

 the surface or of others immediately sub- 

 jacent. Harvey, Thwaites, Priugsheim, and 

 others regard these bodies as (/emmiiles or 

 gonidia; Decaisne, J. Agardh, and other 

 Algologists regard them as true spores. 

 Pringsiieim states that in Cerammm they 

 grow up at once into a thallus. 



The true spores are simpler structures 

 than the tetraspores, but mostly occupy a 

 more important position. They are never 

 scattered through the frond, but always 

 grouped in definite masses, generally enclosed 

 in a special capsule, conceptacle or cystocarp, 

 which is furnished with a closed tube or 

 trichoyync (PL 4. fig. 12 c). In fertilization, 

 the spermatozoids conjugate with the tricLo- 

 gyne (PL 4. fig. 12 a). Its basal cell then 

 subdivides, the new cells forming a sporife- 

 rous heap ; as in Nemalvon (and JBcdracho- 

 spermum). Or, the trichogyne-cell takes 

 no direct part in the formation of the spores, 

 which are produced after fertilization in 

 laterally arising new cells, as in the Cera- 

 miaceje &c. In Diidresnaya the elongated 

 trichogyne is spiral at the base. After its 

 fertilization, cells sprout from beneath it, 

 and elongate to form connecting tubes, 

 These pass over the ends of tlie fructiferous 

 branches, which aVe short with an enlarged 

 terminal cell, becoming soldered with them 

 at the points of contact, the contents being 

 mixed: each connecting tube conjugates 

 witli several of the fertile branches. 



The simplest form of the spore-fruit con- 



