364 



BOTANY AND PHARMACOGNOSY. 



The leaves and bark of the cultivated oleander {Ncri]iui Olean- 

 der) contain the glucoside oleandrin, resembling digitalin in its ac- 

 tion ; a fluorescent principle, and probably several other principles. 



Fig. 173. A, cells of endosperm of the seed of the date palm {Phanix dactylifera) , the 

 one normal and the other showing the stratification of the wall after treatment with 

 chlor-zinc-iodide. 



B, cell of endosperm of PhytelepJtas macrocarpa (vegetable ivory) showing lamellation 

 and spherite structure in the wall after treatment with chlor-zinc-iodide, clove oil, chromic 

 acid or certain other reagents. 



C, cell of endosperm of Strychnos Nux-vomica after treatment with iodine and potas- 

 sium iodide solution. 



D, opposite pores in the walls in contiguous cells of vegetable ivory showing striae 

 between them after treatment with iodine solution. 



The common periwinkle {Vinca minor) contains the principle 

 vincin which is supposed to be a glucoside and which probably 

 occurs in other species of Vinca. 



