CALIFORNIA PLANTS IN THEIR HOMES 



castor-oil seedling, for instance, is really a community of 

 millions of protoplasts, each living in a room made by 

 itself. To see this you must have very thin slices of the 

 plant under the microscope. The little rooms or cells are 

 by no means all alike. To give you some idea of what the 

 cells of the stem are like, two slices, one crosswise and one 

 lengthwise, have been combined in drawing No. 2, Fig. 10, 



Fig. 10. CASTOR-OIL PI,ANT Acinus. 

 1. Epidermis, x 75. 2. Cellular structure of stem, x 150. (Diagramatic.) 



Some cells, you see, are like the water-net cells, with thin 

 walls ; others are much more slender and have thicker 

 walls ; others are very long and have curious markings on 

 their walls. These last two kinds of cells make up woody 

 fibre like those colored by the ink. 



No. i, in the same drawing is the skin, or epidermis, of 

 the leaf under the microscope. Most of the cells are thin 

 and flat, and fit closely together like tiles, but among them 

 are pairs of cells with openings between them, so that each 

 pair resembles open lips. The openings are called pores, or 



