6o 



THE SCIENCE OF LIFE. 



marked with depressions, or concave spaces, (glands?) 

 the centers of which are penetrated, as if some sort of 

 special communication existed between the bioplasm 



FIG. 12. Glandular fiber, a. External appenr.-uire. b. The sides of two tubes, or fibers, 

 in contact, c. d. Lenticular cavity between the lubes. 



of contiguous cells. (Fig. 12.) Sometimes sclerogen is 

 deposited within the cell-wall in such a manner as to 



produce dots, or pores, or rings, 

 or spiral fibers, which give 

 names to the several kinds of 



FIG. 13. Annular and dotted cells. Cells. (Fig. 13.) 



12. Vegetable cells are of various shapes, according to 

 the purposes they subserve. They may be conical, oval, 

 prismatic, cylindrical, sinuous, branched, entangled, or 

 stellate. (Fig. 14.) Tubes, or vessels, are formed of 

 elongated cells. Sometimes such cells join end to end, 

 and the partition being removed by absorption, a long 

 tube is formed. Such vessels may be dotted, reticu- 

 lated, annular, or spiral, from the deposit of woody 

 tissue, or sclerogen. (Fig. 15.) In the stem of Endog- 

 enous plants, as palms, etc., bundles of fibre-vascular 



