68 



Elementary Biology. 



thereby at once indicating the multicellular origin of the 

 mass. It must be clearly remembered that no hard and fast 

 lines can be drawn with reference to such phenomena ; 



FIG. 16. WHITE FIBRO-CARTILAGE FROM AN INTERVRRTEBRAL DISK (HUMAN). 

 HIGHLY MAGNIFIED. (Schafer). 



The concentric lines around the cells indicate the limits of deposit of successive cap- 

 sules or cell-walls. 



animal cells, for instance, especially those entering into the 

 formation of the supporting system, have very distinct cell- 

 walls, though not of cellulose (fig. 16). The absence of the 

 power of motion in these cells is to be noted. 



The author is indebted for many of the generalisations discussed 

 in this chapter to the works of his friend Mr. Patrick Geddes, Lecturer 

 on Botany in University College, Dundee. 



