33 
And with respect to animals, of which we are at the head, 
how vast is the instruction to be found in their history and 
organization! It may be said, indeed, that God could, if 
he pleased, have made animals and plants to live with- 
out an atmosphere ; but we have nothing to do with that :— 
it is sufficiently obvious, that man, animals, and plants could 
not, constructed as they are, have existed in this world with- 
out oxygen. Respiration is a necessary and unavoidable 
function attached to our being. We cannot live unless we 
breathe; and whatever may be the constitution of the in- 
habitants of other worlds, and whatever may be the laws to 
which they are subjected, the breathing of air in this is ab- 
solutely necessary to our existence. 
With respect, Gentlemen, to the growth of seeds, I must 
farther observe, that the presence of air is of the earliest ne- 
cessity ; for though they are covered by the earth, still the 
air reaches them, unless the ground be composed of stiff 
clay, in which the seed might be shut up from the air, and 
consequently would not germinate. From this you will be 
aware, that the process of ploughing and harrowing serves 
a farther purpose than merely loosening the ground, that 
the roots may the more easily penetrate. It serves also to 
give the air a free entrance, and there is a provision in the 
structure of the seed itself which is usetul to this end ;— 
there is an aperture or foramen which passes through the 
husk or coating of the seed, and leads in to the radicle, and 
through this the air of the atmosphere finds an entrance. I 
believe that it exists in all seeds, though in many it is too 
small to be detected, without using a high magnifier. 
Whether there is any peculiar provision in the seeds of 
aquatic plants, to enable them to separate the air from wa- 
ter, I know not. 
