76 



BOTANY. 



specimene may be transferred to a glass slide and dissected by tapping 

 gently upon thu centra of the cover-glass. 



103. — Laticiferous Tissue. In many orders of Phanero- 

 gams tissues are found whose component elements contain a 

 milky or colored fluid — ^the latex. To these, although Tary- 

 ing greatly in structure and position, the general name of 

 Laticiferous tissues has been given. For the sake of simpli- 

 city two general forms may 

 be distinguished : (1) that 

 composed of simple or branch- 

 ing elements (Fig. 64), which 

 are scattered through the 

 other tissues. As found in 

 Eupliorhiacem, where they oc- 

 cur in parenchyma, they are 

 somewhat simply branched, 

 and have very thick walls 

 (Pig. 64, B) ; in other orders 

 they are thin walled and are 

 sometimes inclined to anasto- 

 mose. From their position it 

 is quite certain, that the ele- 

 ments of this form of laticif- 

 erous tissue frequently replace 

 bast fibres. In such cases 

 T,. „ - ,. .. „ , XV they are said to be metamor- 



Fig. 66 — Laticiferona cells of the onion, •' 



from a longitudinal seciion of a scale of phosed bast fibres , m other 

 the hulb. 6, epidermis with cuticle c ; p. , 



parenchyma ; sg, coagulated contents of CaSCS, hOWever, they appear 

 laticiferouscells, contracted 80 as to show iiv j!j.i- 1 li 



the porous walls ; g, g, transverse wall.— not tO 06 01 thlS nature, DUt 



^"^' ^*'=^'- to arise from the parenchyma 



by the absorption of the horizontal partition- walls, f 



* There is an objection to tlie word metamorphosed in this connec- 

 tion, as it does not exactly express the relation between the laticiferous 

 elements and the bast fibres. It must not be understood that the 

 former are made by a transformation of the formed bast fibres ; the 

 relation is rather that they develop from what under other circum- 

 stances would have developed into bast fil)res. We may express the 

 relation by saying that laticiferous elements and bast fibres are closely 

 related sister elements. 



•f " According to Hanstein, it is probable that in some Aroidese vessels 



