6/51 I will first give a case among the Reptilia from some of Mr.Darwin's unpublished MSS., which have been kindly lent me by Mr.Francis Darwin. Milne Edwards (_Annales des Sci. 50) has given a curious table of measurements of fourteen specimens of Lacerta muralis; and, taking the length of the head as a standard, he finds the neck, trunk, tail, front and hind legs, colour, and femoral pores, all varying wonderfully; and so it is more or less with other species. So apparently trifling a character as the scales on the head affording almost the only constant characters." [Illustration: FIG. |