Some people object that in order for the eye to modify and still remain a useful instrument to its owner, many changes would have had to take place simultaneously. However, it is not necessary to suppose this if the modifications were extremely slight and gradual.
juv27
Some people object that in order for the eye to modify and still remain a useful instrument to its owner, many changes would have had to take place simultaneously. However, it is not necessary to suppose this if the modifications were extremely slight and gradual.