...His successors, unable to accept this concession to Lamarckianism, criticised his statement that " it is difficult to imagine that eyes, though useless,...any way injurious to animals living in darkness," and strove to show that natural selection would account for their disappearance. How difficult was...

...attributed to a double cause : disuse and natural selection. As it is difficult to imagine [he wrote] that eyes, though useless, could be in any way injurious to animals living in the darkness, their lose may be attributed to disuse. [And further on : ] By the time that an animal...

...attributed the atrophy of the eyes of cave animals to disuse, not to natural selection, because he found it "difficult to imagine that eyes, though useless, could...any way injurious to animals living in darkness." 82 Among Agassiz's students, Hyatt and Shaler had already visited the Mammoth Cave in 1859, but for...

...not functionally blind) led Darwin to view the loss of eyes in cave animals as the result of disuse. eyes, though useless, could be in any way injurious...darkness, their loss may be attributed to disuse" (ibid., p. 135). To explain other cases where there were clear losses of morphological structure, Darwin...

...organ would thus be determined, to a considerable degree, by active natural selection. So, in general, "as it is difficult to imagine that eyes, though useless,...in any way injurious to animals living in darkness, 1 attribute their loss wholly to disuse."2 As is well known, scientists fall into two camps on the...

...from random mutation alone and requires no additional selective mechanism. Darwin put it this way: "As it is difficult to imagine that eyes, though useless, could be in anyway injurious to animals living in darkness, I attribute their loss wholly to disuse." ' 1 Loss...

...classes, which inhabit the caves of Styria and of Kentucky, are blind. In some of the crabs the foot-stalk for the eye remains, though the eye is gone; the stand...in any way injurious to animals living in darkness, I attribute their loss wholly to disuse. In one of the blind animals, namely, the cave-rat, the eyes...

...that these animals lost their eyes through the law of disuse and not by means of natural selection ('As it is difficult to imagine that eyes, though...in any way injurious to animals living in darkness, I attribute their loss wholly to disuse' (n7)).20 Third, he argued that on 'my view' one would expect...

...is well known that several animals, which inhabit the caves of Carniola and Kentucky, are blind. ... As it is difficult to imagine that eyes, though useless,...darkness, their loss may be attributed to disuse" (Darwin 1859, 135). As was generally the case, Darwin appealed to the effects of disuse only when no...

...Kentucky are blind. In some of the crabs the foot-stalk for the eye remains, though the eye is gone. As it is difficult to imagine that eyes, though useless,...In one of the blind animals, namely, the Cave-rat (Neotoiiia), two of which were captured by Professor Silliman, at about half a mile distant from the...