286 THE HISTORY OF CREATION. 
leads to a partial degeneration, and finally even to the loss 
of individual organs, is, when looked at by itself, a degenera- 
tion, but yet may be advantageous to the organism in the 
struggle for life. It is easier to fight when useless baggage 
is thrown aside. Hence we meet everywhere, in the more 
highly-developed animal and vegetable bodies, processes of 
divergence, the essence of which is that they cause the 
degeneration, and finally the loss, of particular parts. And 
at this point the most important and instructive of all the 
series of phenomena bearing upon the history of organisms 
presents itself to us, namely, that of rudimentary or 
degenerate organs. 
It will be remembered that even in my first chapter I 
considered this exceedingly remarkable series of phe- 
nomena, from a theoretical point of view, as one of the 
most important and most striking proofs of the truth 
of the doctrine of descent. We designated as rudimentary 
organs those parts of the body which are arranged for a 
definite purpose and yet are without function. Let me 
remind the reader of the eyes of those animals which 
live in the dark in caves and underground, and which con- 
sequently never can use them. | In these animals we find 
real eyes hidden under the skin, frequently developed 
exactly as are the eyes of animals which really see; 
and yet these eyes never perform any function, indeed 
cannot, simply for the reason that they are covered by 
an opaque membrane, and consequently no ray of light 
falls upon them (compare above, p. 13). In the ancestors 
of these animals, which lived in open daylight, the eyes 
were well developed, covered by a transparent horny 
capsule (cornea), and actually served the purpose of 
