OF ORGANIC NATURE 21 



essential feature one from the other ; there is a time when 

 they each and all of them resemble this one of the Dog. 

 But as development advances, all the parts acquire their 

 speciality, till at length you have the embryo converted 

 into the form of the parent from which it started. So that 

 you see, this living animal, this horse, begins its existence 

 as a minute particle of introgenous matter, which, being 

 supplied with nutriment (derived, as I have shown, from 

 the inorganic world), grows up according to the special 

 type and construction of its parents, works and undergoes 

 a constant waste, and that waste is made good by nutriment 

 derived from the inorganic world ; the waste given off in 

 this way being directly added to the inorganic world ; and 

 eventually the animal itself dies, and, by the process of 

 decomposition, its whole body is returned to those con- 

 ditions of inorganic matter in which its substance originated. 



This, then, is that which is true of every living form, 

 from the lowest plant to the highest animal to man him- 

 self. You might define the life of every one in exactly 

 the same terms as those which I have now used ; the 

 difference between the highest and the lowest being simply 

 in the complexity of the developmental changes, the 

 variety of the structural forms, the diversity of the physio- 

 logical functions which are exerted by each. 



If I were to take an oak tree as a specimen of the plant 

 world, I should find that it originated in an acorn, which, 

 too, commenced in a cell ; the acorn is placed in the ground, 

 and it very speedily begins to absorb the inorganic matters 

 I have named, adds enormously to its bulk, and we can 

 see it, year after year, extending itself upward and down- 

 ward, attracting and appropriating to itself inorganic 

 materials, which it vivifies, and eventually, as it ripens, 

 gives off its own proper acorns, which again run the same 

 course. But I need not multiply examples, from the 

 highest to the lowest the essential features of life are 

 the same, as I have described in each of these cases.. 



So much, then, for these particular features of the 

 organic world, which you can understand and comprehend, 

 so long as you confine yourself to one sort of living being, 

 and study that only. 



But, as you know, horses are not the only living creatures 

 in the world ; and again, horses, like all other animals, 

 have certain limits are confined to a certain area on the 

 surface of the earth on which we live, and, as that is the 



