THE EVIDENCE FROM DEGENERATION. 365 



favourable aspect in relation to progress and evolution. High 

 authority in matters biological may be found for the statement that 

 degeneration is really a result of progress, that it is dependent on 

 high development, and that, whilst it simplifies the living being, " it 

 produces the same effect as differentiation, for it leads to variety in 

 form." Thus there is a kind of evolution and progress inseparable 

 even from degeneration itself. For the retrogression may in itself 

 lead to variety and change, and in due time such variety may be the 

 starting-point of new and higher developments. So, likewise, we 

 are reminded that reduction and degeneration of some parts may 

 proceed contemporaneously with the higher development of others, 

 with the total result of perfecting the organism, and of evolving a 

 higher type of structure. The degeneration of a frog's tail is in 

 reality a feature of its higher type as compared with its tailed friends 

 the newts and salamanders. The disappearance and reduction of 

 the tail which the young crab possesses, is a chief reason why we 

 esteem the crab, whose body is all head and chest, a higher animal 

 than the lobster or prawn with head, chest, and tail complete. The 

 degeneration of the " outside " gills of the Alpine salamander's young, 

 which never have access to water, is not a mark of inferiority but of 

 superiority ; it is, in reality, the casting-off of the old or larval and 

 aquatic characters and the putting on of the new and higher features 

 of the land animal. Even the degeneration of human structures 

 the modification of the tail which early human existence exhibits, 

 and of muscular structures well developed in lower life are no 

 proofs of inferiority, but are evidences of superiority in ourselves. 

 Thus, even in the great work of evolving higher races out of the 

 lower, to degeneration much is owing for its aid in repressing larval 

 characters and the structures which belong to lower existences. 

 Whilst progressive evolution develops the great tree of life, extends 

 each branch, clothes it with verdure, and expands each blossom, it 

 is degeneration which lops the worn and aged stems, prunes the 

 weakly foliage, trims the budding growths, and so directs and moulds 

 the outlines of the organic whole. It is to evolution and progress 

 that the world of life largely owes its forward march. But hardly 

 less is the debt of gratitude due by the living hosts to degenerative 

 change and retrogression which, though stern and ofttimes cruel in 

 their ways, nevertheless mark wisely and well the pathways of life, 

 and prevent the useless and weak from cumbering the ground. 



