140 PART II. THE INTIMATE STRUCTURE OF PLANTS. [ 29. 



contain mucilage, as in the parenchyma of Tiliacese and Malvaceae, 

 in the bark of Elms and Firs, in the pseudo-bulbs of Orchids, etc.: 



A 



FIG. 101. Lysigenous oil-gland below 

 the upper surface of the leaf of Dictam- 

 nus Fraxinella ( x 320). B At an early 

 stage ; C mature ; c mother-cells of the 

 gland before their absorption ; o a large 

 drop of ethereal oil. (After Sachs.) 



Fis. 102. Schizogenous resin-duct in the 

 young stem of the Ivy (Hedera Helix), transverse 

 section ( x 800). A An early, E a later, stage ; 

 g the resin-ducts; c the cambium; wb the soft 

 bast ; b bast-fibres ; rp cortical parenchyma. 

 (After Sachs.) 



FIG. 103. Sac containing a crystal, 

 from the leaf of Rhamnus Frangula : e 

 upper epidermis; p palisade-tissue: c 

 chloroplastids ; fc the crystal, (x 200.) 



FIG. 104. Part of section of the petiole 

 of the Camphor-tree (Cinnamonum 

 ), showing a resin-sac h. 



the cells which contain tannin, as in many Ferns and other plants : 

 the cells which contain oil-resin as in the Laurineey (Camphor, Fig. 

 104), the Zingiberacese, many Conifers (wood of Silver Fir), etc. 



