USES OF STOilATA. 41 



which may be seen with a common magni- 

 fying glass, is caused by alternate longitudinal 

 partitions of the barlv, the one imperforate and 

 the other furnished with one or two rows of 

 pores or piouths, shut in dry, open in Tvet 

 weather, and each calculated to imbibe fluid 

 whenever the straw is damp. Pores, or 

 mouths, similar to these, are placed by nature 

 on the surface of leaves, branches, and stems of 

 all perfect plants ; a provision, indeed, intended 

 no doubt to compensate in some measure the 

 want of locomotion in vegetables. A plant 

 cannot, when thirsty, go to the brook and 

 drink ; but it can open innumerable orifices 

 for the reception of every degree of moisture 

 which either falls in the shape pf rain and of 

 dew, or is separated from the mass of fluid 

 always held in solution in the atmosphere. It 

 seldom happens in the driest season that 

 the night does not afford some refreshment 

 of this kind, to restore the moisture that 

 has been exhausted by the heat of the pre- 

 ceding day." The writer then proceeds to 

 say that it is by these pores, or stomataj 

 as we have called them, the seeds of the 

 fungus gain admission ; and with respect to 

 the one now before us he is right, according to 

 b3 



