4 VEGETABLE PHYSIOLOGY. 



eye. This will be easily conceived by looking at a 

 slice of common sponge ; but the annexed sketches 

 will assist to give a better idea of its structure than 

 any language which it is in the writer's power to 

 employ. Of course they are drawn highly magni- 

 fied for the sake of distinctness. 



The sketch, Fig. 1, represents cellular matter as 

 it appears when expanded perpendicularly, as in 

 the pith, in the leaf-stalks of herbs, and in other 

 parts of plants. 



Fig. 1. 



s 



Fig. 2 shows it as swelling laterally, from right 

 to left, as in the concentric layers of wood. 



Fig. 2. 



In the crown of an Agaricus* it appears depressed, 

 as at Fig. 3. 



f Mushroom. 



