THE LOWER FOEMS OF LIFE. 



chemical combinations, or electricity, or heat ; but such reasoners 

 make no real progress in the inquiry. Life is the great antagonistic 

 principle to chemical forces, and hence arises an insurmountable 

 difficulty in proving that one is a correlation of the other. Elec- 

 tricity may be a correlation of heat, because they can, it is said, be 

 converted into each other. Neither of them, however, will give life 

 to an inanimate or unorganised body. 



And so it arises that there is great beauty in the provision which 

 is fore-ordained that the life of the organised grain of wheat should 

 remain dormant until the circumstances necessary for its existence 

 as a living thing are presented to it. These circumstances are the 

 united presence of heat, moisture, and atmospheric air. This 

 dormant condition of the seed is therefore one of the attributes of 

 life. That the life, though dormant, is really a powerful force is 

 proved by the fact that it prevents the constituents of the seed from 

 being subject to the chemical forces which decompose and re-arrange 

 the elements of dead matter. So long as the above conditions 

 heat, moisture, air are kept away from the seed, its vitality will 

 lie dormant, and its physical condition remain unaltered for any length 

 of time that the imagination can depict. 



But the wheat-seed has a great and 

 important office to fulfil in the world. 

 Its destiny is more or less connected 

 with that of the whole human race. It 

 is the means by which that daily prayer, 

 " Give us this day our daily bread," is 

 answered, and due provision made that 

 it should perform the duties for which 

 it was created, Brought under the 

 united influence of heat, moisture, and 

 atmospheric air, all of which it meets 

 with in the soil, we see a very beautiful 

 process the seed germinates. 



Now let us for a moment examine 

 Fig. 2, which represents a longitudinal 

 section of a grain of wheat, with the 

 parts of the germ or embryo enlarged 

 (after Henslow). 



First observe the two skins or cover- 

 ings, one (a) is called in botanical 



language the "pericarp" or outer skin, and (b) the "endocarp" 

 or integument or inner skin. These skins are well known to 

 millers, for the thinner they are the more flour and less bran is 

 yielded to the grindstones. At the top of the section (c) is the 



