To prove that this is not an isolated case, Professor Milne Edwards also
gives a table showing the amount of variation in the museum specimens of
six common species of lizards, also taking the head as the standard, so
that the comparative variation of each part to the head is given. In the
accompanying diagram (Fig. 2) the variations are exhibited by means of
lines of varying length. It will be understood that, however much the
specimens varied in _size_, if they had kept the same _proportions_, the
variation line would have been in every case reduced to a point, as in
the neck of L. velox which exhibits no variation. The different
proportions of the variation lines for each species may show a distinct
mode of variation, or may be merely due to the small and differing
number of specimens; for it is certain that whatever amount of variation
occurs among a few specimens will be greatly increased when a much
larger number of specimens are examined. That the amount of variation is
large, may be seen by comparing it with the actual length of the head
(given below the diagram) which was used as a standard in determining
the variation, but which itself seems not to have varied.
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