BOTANICAL CHARACTERS 



85 



off from the leaf-surface, and is replaced by a fresh supply CHAP 

 drawn up from the roots. Frank (1) notes that a single IV " 

 maize plant can pass off into the atmosphere 31 lbs. weight of 

 water in 147 days of growth. This is less than the amount 

 lost by some other plants, e.g. : — 



The maize plant can lose 31 lbs. in 147 days. 

 The hemp ,, 60 „ in 140 „ 



The sunflower ,, 147 ,, in 140 ,, 



The rate of transpiration is greater in light than in dark- 

 ness. In the maize plant 

 it has been found to vary 

 in the following ratio : — 



In darkness . . 97 



In diffused light . 1 14 

 In direct sunshine 785 



There is thus a stream 

 of water constantly pas- 

 sing away from the soil 

 into the air, through the 

 leaves of the plant ; it 

 soon drains the soil dry 

 unless replaced by rain 

 or irrigation. It has been 

 found that 500 tons of 

 water (containing salts 

 in solution) is required - 

 to form one ton of dry 

 matter (Bowman and 

 Crossley, 1). 



The leaves are ar- 

 ranged distichously, i.e. 

 in two opposite rows, 

 but there is no uni- 

 formity as to the direc- 

 tion in which the TOWS FlG _ 2g ._Young ear showing silks ready 

 point. for first pollination ; the husks have developed 



70. The Inflorescence. ] ea [ b , lades - showin s the homology of husk and 



J leaf sheath. 



— The maize plant is 



monoecious, i.e. it bears the reproductive organs in separate 



flowers on the same plant (Fig. 1 2). The staminate or male 



