Regeneration and Liability to Injury

exists a relation between the power of regeneration of a part and its liability to injury. Certain well-established facts in regard to the regeneration of internal organs are entirely overlooked or disregarded in the attempt to show that the above relation explains the origin of regeneration. It would be interesting if those who hold that there is no such thing as a general power of regeneration; in each kind of animal this power is graduated according to the need of regeneration in the part under consideration, it would be interesting if such persons would show how such a thing could arise by means of variation and survival of the fittest.