CELL-CONTENTS AND FORMS OF CELLS. 289 



FlG. 155. Characteristic branching hairs found on the stem, leaves, and calyx of 



Hyoscyamus muticus, 



stinging hairs of some of the Euphorbiaceae, as well as in some of 

 the genera of the Cornaceae, Geraniaceae, Rosaceae, and Saxi- 

 fragaceae. 

 19 



