CHAPTER IV 



LATEX 



Laticiferous Tissues of Plants. — The latex of plants is 

 contained in a system of special tubes, vessels, or cells 

 which are usually present in every part of the plant, in 

 the root, stem, branches, leaves, and fruit. Three types 

 of laticiferous tissue occur in plants, viz. non-articulated 

 tubes, articulated vessels, and single cells (sacs), and 

 examples of each of these forms are found amongst the 

 rubber-yielding plants. 



The non-articulated tubes are developed from special 

 laticiferous cells present in the embryo which grow and 

 branch in the tissues as the plant increases in size. These 

 cells may therefore attain an enormous length and they 

 are not divided in any way. Such elongated laticiferous 

 tubes are present in the seedlings of Castilloa elastica, 

 Funtumia elastica, and other rubber-yielding plants. 



The articulated vessels, on the other hand, are developed 

 in the tissues from longitudinal rows of special cells. The 

 transverse walls of these cells undergo absorption forming 

 long, continuous tubes (vessels) which become filled with 

 latex. The adjacent vessels frequently communicate 

 with one another by lateral passages, and thus produce 

 a complete network in the tissues. Articulated laticifer- 

 ous vessels of this type are well seen in Hevea hrasUiensis, 

 the Para rubber tree, and in Manihot Olaziovii, the Ceara 

 rubber tree. 



A third type of laticiferous tissue consists of isolated 

 cells wliich arc ]<nown as sacs. These cells are frequently 

 arranged in longitudinal rows, but they do not com- 

 municate with one another. This form is not common 

 amongst rubber plants, but it occurs in the (ruayulc plant, 

 Partlienlum arqcntatuvi, A. Cray, belonghig to the natural 

 order Compositae, and it is also met with in the trees which 



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