TISSUES AND SIMPLE ORGANS. 



125 



FIG. 69 A. Vertical section through 

 the leaf of Sambucus nigra. " Arm- 

 palisades. " 



(After Haberlandt.) 



FIG. 71. Vertical section through 

 the leaf of Juglans regia. 



Palisade-cells are supposed to be richly, 

 the spongy tissue cells less richly, sup- 

 plied with chlorophyll. Both cell-forms 

 are here typically developed. (After 

 Haberlandt.) 



FIG. 69 B. Vertical section through the leaf, including the midrib, of Rapha- 



nus sativus. 

 (After Haberlandt.) 



]? IG 70. Vertical section through the leaf of Ficus 

 elastica. The epidermis is omitted. 



v and pi, Palisade-cells ; a, collecting cells ; s. p 



sheath ; y, vascular bundle. (After Haberlandt.; 



FIG. 72. Lower surface of 

 an *' isohiternl " leaf, Sil- 

 phi'iim laciniatum. 

 (After Haberlandt.) 



