MICROSCOPE IN THE GARDEN. 33 



it under the Microscope, the cellular structure of 

 plants may be observed in all their soft parts. 



If, now, we take a thin section from an apple, or 

 other soft fruit, or from a growing bud, or tuberous 

 root, as the turnip, we shall find that many of the 

 cells contain in their interior a " nucleus," or 

 central spot, a representation of which is seen 

 from the cells of an apple in figure 1 of the first 

 plate. This nucleus is a* point of great import- 

 ance in the history of the cell, for it has been 

 found that the cell originates with it, and that all 

 cells are either formed from a nucleus of this kind, 

 or by the division of a thin membrane in the inte- 

 rior of the cell, which represents the nucleus, and 

 is called a " primordial utricle." 



When the cells of plants have thus originated, 

 they either remain free or only slightly adherent to 

 each other, or they press upon each other, assuming 

 a variety of shapes ; they then form what is called 

 a " tissue." When cells are equally pressed on all 

 sides, they form twelve-sided figures, which, when 

 cut through, present hexagonal spaces. This may 

 be seen in the pith of most plants, more especially 

 the common elder, which is seen at figure 2 of 

 plate 1. Transverse slices of the stems of any 

 kind of plant from the garden may be made by a 

 razor, or sharp penknife, and will afford interesting 

 objects for the Microscope. 



Cells, during their growth, assume a variety of 

 shapes, and the tissues which they form are named 

 accordingly. Two examples of such cells will be 

 seen in figures 243 and 244 in plate 8, where the 

 first represent cells from the hard shell of a plum 

 stone, and the second the thin cells from the out- 

 side of the seed of the guelder rose. 'Sometimes the 

 cells are very much elongated, or they unite together 

 to form an elongated tube ; the tissue thus formed is 



