90 



VIEWS OF THE MICROSCOPIC WORLD. 



placed side by side, but always alternate with each other. The first disk of one row, 

 for example, being placed opposite the vacant space separating the first and second 

 disks of the adjoining row. The disks of the Araucarias are not more than one 

 half the size of those belonging to the real pines, and are so numerous that Mr. 

 Nicol counted as many as fifty in a row, one-twentieth of an inch in length. 

 The diameter of a disk, allowing that they touched each other, could therefore 

 not exceed the thousandth part of an inch ; a magnitude of vast extent com- 

 pared with the thickness of those infinitely slender fibres, which, woven together 

 into an exquisitely delicate tissue, form the partitions of the numerous cells of the 

 trunk. 



Fig. 140. 



