Vegetable Productions. 81 



ting a round hole in a cardboard box, blackening the 

 latter, placing a lens inside, and slipping it on to the 

 lower end of the tube (No. 7). It answered exceed- 

 ingly well for opaque objects, though showing its non- 

 achromatic short-comings when used with transmitted 

 light. 



For the benefit of those who wish to go deeper 

 into the interesting subject of the structure of 

 plants, I will name a few of the most characteristic 

 objects which can be procured from the vegetable 

 kingdom. 



Cuticles. The cuticle is that transparent skin 

 which peels easily off the leaves of the lily, and 

 various other plants, and off the petals of flowers. 

 The microscope shows that it is formed of one layer 

 of cells, containing air, and serving to protect the 

 fluid-filled cells within ; yet, as these latter require 

 the entrance of a due proportion of outer air, the 

 cuticle is fitted up with ventilators in the form of 

 pores, called the stomata, curiously arranged to open 

 and shut. 



The internal cells of plants. " The origin of every 

 plant is a single cell ; the perfection of a plant, from 

 the tiniest moss to the loftiest oak, is in a countless 

 multitude of simDle cells, containing various sub- 

 stances needful for its growth, and of an infinite variety 

 of shape and substance."* 



Cell- contents. Starch-granules abound in the cells 

 of a good potato, and (according to Dr. Carpenter) 

 " in some part or other of most plants." Oil is con- 



* " Objects for the Microscope," p. 13. 



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