I 



CARPOSPOREm. oH 



9 



with few exceptions {Batrachospermum, Hildenbrandtia'^), to the sea. In the normal 

 condition they are of a red or violet colour ; the green colour of their chlorophyll is 

 concealed by a red pigment^, soluble in cold water. 



The Thallus of the Florideae consists, in the simplest forms, of branched rows of cells, 

 which elongate by apical growth and transverse division of their apical cell. An appa- 

 rent formation of tissue occurs in many Geramiaceae (G. Cramer, Physiolog. u. system. 

 Untersuch. liber die Geramiaceen, Zurich, 1863) from the branches growing closely 

 adpressed to their mother-axes, and thus surrounding them with a cortex, reminding one 

 of the formation of the cortex in Char a. In other Florideae the thallus is a flat expan- 

 sion of cells, but often consisting of several layers ; in some (as Hypoglossum and Deles- 

 seria) it assumes the contour of stalked leaves, even the venation being represented; in 

 others {e.g. Sphxrococcus and Gelidium) it consists of filiform or narrow strap-shaped 

 masses of tissue, which ramify copiously {e.g. Plocamium, Sec). In all these cases Nageli 

 asserts (Neuere Algensysteme, p. 248) that apical growth takes place from an apical cell 

 (in Peissomelia possibly from several). In the simpler forms the segments of the apical 

 cell are formed in one row by transverse divisions, in others in two or three rows by 

 oblique walls. One group which comprises a large number of species, the Melobesiaceae 

 (RosanofF, Mem. de la Soc. Imp. des Sci. Nat. de Gherbourg, vol. XII. 1866), forms disc- 

 like thallomes, which grow centrifugally at the circumference and are closely attached 

 to the substance on which they grow, which generally consists of larger Algae; they 

 resemble Coleochxte scutata in their size and mode of life, but their thallome generally 

 consists of several layers, and the cell-wall is encrusted with lime. 



The asexual organs of reproduction are gonidia: since four are usually formed in 

 a mother-cell, they are termed Tetragonidia, but sometimes only one, or two, or eight 

 are formed. They do not occur in the Nemalieae. When the thallus consists of rows of 

 cells, the tetragonidia are produced in the apical cell of lateral branches ; in the rest (with 

 the exception of the Phyllophoraceae, according to Nageli) they lie imbedded in the tissue 

 of the thallome, often in branches of peculiar shape, in great numbers. 



The sexual organs, antheridia and carpogonia, are produced on other plants of the 

 same species; the sexual plants are frequently dioecious. 



Sitzungsb. der k. bayer. Akad. der Wissen.— Eornet and Thuret, Ann. des Sci. Nat. 5th series, 



vol. VII. 1867. — Solms-Laubach, Bot. Zeitg. nos. 21, 22, 1867. [See also Agardh, Florideernes 



Morphologie, 1880; Kny, Ueb. Axillarknospen bei Florideen, 1873; Thuret, Etudes phycologiques, 



1878; Bornet et Thuret, Notes Algologiques, 1876-80; Janczewski, Le developpement des cysto- 



carpes dans les Floridees, Cherbourg, 1876; Berthold, Zur Kennt. d. Bangiaceen (Mitth. d. Zool. 



Stat. z. Neapel, 1880) ; Sohns-Laubach, Corallineen (Fauna u. Flora d. Golfes von Neapel, 1881).] 



^ [Also Lemaneacese, Sirodot, Ann. des Sci. Nat. 5th ser. 1872, vol. XVI, and Bangia^ 



^ Rosanoff extracted the red colouring matter by cold water, and examined it accurately. In 



] transmitted light it is carmine-red, in reflected reddish-yellow ,- the grains of chlorophyll also show 



j this fluorescence, and when the red colouring matter (the phycoerythrine) has escaped from them in 



! consequence of injury to the cells they are green ; the whole plant also remains green when the red 



colouring matter has been extracted by water or destroyed by heat. (Rosanoff in Compt. Rend. 



April 9, 1866.) Besides the chlorophyll-granules coloured red by phycoerythrine, Cohn found in 



,■ Bornetta colourless crystalloids of an albuminous substance which are coloured a beautiful red by the 



Jj colouring matter that escapes from the chlorophyll-granules when the cells are injured or killed. 



] (Schultze's Arch, fiir mikr. Anat. Ill p. 24.) Cramer had previously observed crystalloids of this 



'j kind in Borneiia vihich had been preserved in a solution of sodium chloride, and had accurately 



H described them; according to him they are partly hexagonal, partly octahedral (Rhodospermin). 



I, (Vierteljahrschr. der naturf. Ges. in Zurich, vol. VII.) Julius Klein (Flora, no. 11, 1871) found 



colourless crystalloids in Griffithsia harhata and neapolitana, Gongoceras pellucidum, and Cnllithamnion 



seininudiim ; and states that the red crystalloids v/hich are also found outside the cell-cavity only 



, appear after treatment with sodium chloride, alcohol, or glycerine, since their colourless matrix takes 



;,|'up the diffusible red colouring matter of the Florideae. On Phycoerythrine see Askenasy, Bot. Zeitg. 



no. 30, 1867. [Sorby, Monthly Mic. Journ. vol. VI. 1871, p. 124. Van Tieghem has detected starch 



in the Floridex, Compt. Rend. 1865.] 



U 



