13° 



SCLERENCHFMA . 



On the Other hand there commonly occur in Phanerogams fibres which are 

 freely and often abundantly branched, and of a form which varies according to the 

 special place of their occurrence : these usually occur in dissimilar lacunar tissue, 

 with their branches projecting or pushed into its interstices. Inasmuch as these 

 project like many branched hairs into wide, air-containing spaces, as in the Nymphae- 

 ace?e, Limnanlhemum, Aroidece, Rhizophora, the description of them will be more 

 clearly given when we treat of these spaces (Sect. 53), and we need only draw atten- 

 tion here to their connection with the tissues treated of in this chapter. They also 

 occur more especially in numerous tough, leathery foliage-leaves, though not in the ma- 

 jority of them; they push their branches into the intercellular spaces of the parenchyma, 

 and appear to serve as strengthening apparatus for that tissue. With reference to the 

 relations of their arrangement, to be treated in Chaps. IX and X, may here be men- 

 tioned the short-branched fibres in the leof-lamina of Proteacese (Hakea nitida, cera- 

 tophylla, saligna, &c. ^), the long- and finely-branched fibres in the lamina of Olea 

 europcea, emarginaia, fragrans -, the thick, starlike, short-branched ones of Camellia 



Fig. 53. — From a transverse section of the leaf of Camellia japonica. P parenchyiiiatoiis cells, with chlorophyll 

 grains and oil drops ; F thin vascular bundle ; K branched sclerenchyma fibre. From Sachs' Textbook. 



japonica' (F'S- 53)) Statice monopetala, the beautiful stellate, many-armed ones in the 

 lamina and petiole of Fagrsea obovata, and auriculata ^. Also the leaf-lamina of the 

 above-named Aroideae, especially the Monsterineae, and the Nymphaeaceae, may be 

 here again cited. Stellate-branched fibres occur in the foliage-leaf of Sciadopitys, 

 Dammara, Araucaria imbricata*^. Long-branched ones, sometimes of huge size, 

 form at least half of the substance of the leaf in Gnetum Gnemon, and G. Thoa. 



The relation between breadth and length of the fibres varies greatly both ac- 

 cording to species and in different parts of the same species, and in the self-same part 

 and the self-same bundle it often varies within wide limits. This is to be taken 



' Meyen, Harlemer Preisschrift, p. 84, Taf. V. — Mohl, \'erm. .Schr. Taf. VII. fig. 2. — Schleiden, 

 Grundz. 3 Aufl. I. p. 277. 



^ Moldenhawer, Beitrage, p. 61. — Thomas, Lc. p. 32. 



^ Kraus, Cycadeen-fiedern, I.e. p. 327. 



* O. Buch, Ueber Skkrenchymzellen. Diss. Breslau, 1872, p. 16. 



'■' Thomas, I.e. p. 35. — Mohl, Botan. Zeitg. 1871. p. 8. 



