The relation of the blind species of any order of animal life to those having developed eyes is an interesting problem and one that is not yet fully solved. Many observations have been made by various naturalists, the greater number of whom believe that a process of evolution has been effected by the absence of light acting upon forms originally with normally developed eyes. Semper, in his "Animal Life as Affected by the Natural Conditions of Existence," questions the influence of the absence of light in effecting the atrophy of visual organs. Some of his objections are fully answered by Packard in his "Cave Fauna," and the probability is that the results of further investigation will tend to prove the direct effect of absence of light upon atrophy of organs of sight.
Proceedings of the Iowa Academy of Science
©1926 Iowa Academy of Science, Inc.
Ross, L. S.
"Origin of Species Eucrangonyx mucronatus,"
Proceedings of the Iowa Academy of Science, 33(1), 325-328.
Available at: https://scholarworks.uni.edu/pias/vol33/iss1/98