Origin of Species Variorum

Comparison with 1866

looking to distant provinces throughout the world, we find that certain organisms differ little, from each other, whilst others belonging to a different class, or to a different order, or only to a different family of the same order, differ greatly. In both time and space the lower members of each class generally change less than the higher; but there are in both cases marked exceptions to the rule. On my theory these several relations throughout time and space are intelligible; for whether we look to the forms of life which have changed during successive ages within the same quarter of the world, or to those which have changed after having migrated into distant quarters, in both cases the forms within each class are connected by the same bond of ordinary generation; and

looking to distant provinces throughout the world, we find that species in certain classes differ little from each other, whilst those in another class, or only in a different section of the same order, differ greatly from each other. In both time and space the lowly organised members of each class generally change less than the highly organised; but there are in both cases marked exceptions to the rule. According to our theory, these several relations throughout time and space are intelligible; for whether we look to the allied forms of life which have changed during successive ages, ... or to those which have changed after having migrated into distant quarters, in both cases they are connected by the same bond of ordinary generation; ...