76 



BOTANY. 



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

 gently upon the centre of the cover-glass. 



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

 gams tissues are found whose component elements contain a 

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

 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 

 EuphorllacecB, where they oc- 

 cur in parenchyma, they are 

 somewhat simjDly branched, 

 and have very thick walls 

 (Fig. 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 

 _. ,.„ ^ ^. .. „ ,*,, • they are said to be metamor- 



Fig. 06 —Laticiferous cells of the onion, »' > n^ j. • 



from a longitudinal seciion of a scale of phoscd bast fibres :* in other 

 the bulb, e, epidermiB with cuticle c ; p^ , , , 



parenchyma ; sg, coagulated contents of CaSeS, llOWever, they appear 

 laticiferous cells, contracted so as to show j. j. i, ji xi • 1 i j 



the porous walls ; g, ^, transverse wall.— not tO 06 01 tniS nature, but 



Jitter Sachs. ^^ ^^.^^^ ^^^^ ^^^ parenchyma 



by the absorption of the horizontal partition- walls; f 



* There ia an objection to the 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 fibres. We may express the 

 relation by saying that laticiferous elements and bast fibres are closely 

 related sister elements. 



f " According to Hausteiu, it is probable that in some AroidesB vessel? 



