TISSUES. 



159 



TOS, A, Cross-section of Pumpkin vine (x'550); si, walls or septa at the union of cells, developing Into 

 sieve plates; c, c, cambium cells ; p, p, parenchyma. J3, Lengthwise section, showing the enlarged joiD** ; 

 g, an edge view of sieve septa; i, sieve spot on the side-wall. 



408. Latex vessels are 

 produced by the union end 

 to end of latex cells; by 

 anastomosing and branch- 

 ing a reticulated tissue is 

 formed which conveys the 

 milky juices of the plant 

 through its structure. In 

 the tissues of the Ficus 

 elastica, Euphorbia and the 

 milk weeds, besides the 

 Latex tubes, numerous 

 closed cells are present, 

 charged with the same 

 milky fluids as the ducts 

 (Fig. 509). The free cells 

 frequently elongate, and 

 sometimes branch. 



These vessels are ar- 

 ranged in the stem as rep- 

 resented in Fig. 510. 



vessel m r ' 



