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Show 1906.] IN MEXICAN LIZARES. 297 creature's organism itself, since the 20 glands can easily do the extra work between them *. The same reasoning applies to the protection of the forearm. The nature of the ground over which these lizards have to run, conceivably may directly influence, stimulate, these gaiters composed of long rowrs of broad scutes. I leave it open, not always to rouse the anti-Lamarckian ire, whether the scutellation is due to natural selection ; but I want to know why these same scutes are lost again by those delegates of a gaitered kind which have straddled into forests or upon sandy ground. Or, another point of view. The "granulated specimens" of C. mexicanus from Cuernavaca and Cuautla (cf p. 367), or those of C. communis occidentalis from Patzcuaro, should be at such an obvious disadvantage to their gaitered brethren that these tendencies ought to have been eradicated long ago. Would anyone be bold enough to stipulate a physiological difference between the possession of 3 or 4 supraoculars ? Fine, instead of coarse, granulation prevails in the skin of the deppei - group; their whole organism is imbued with this acquired character, and this tendency is likely to spread, to assert itself in all those parts where scales and scutes are not positively required. In most species with normally 4 supraoculars these are bordered behind by one or more rows of granules ; in some specimens the last supraocular is split, or much reduced (e. g. text-fig. 71 A, p. 303), and there are more granules, and granules fill its whole space in the deppei-group, except in those old-fashioned individuals, about 10 per cent, with rather local predilection, which still retain the original number. That is all, neither more nor less! Every normal organism, and its constituent organs jointly or separately, tends towards greater perfection f. It is under the influence of the law of perfection. This must be so unless the whole idea of onward evolution is a dream, and it is a necessary outcome of the principle of the inheritance of acquired characters. * Here we are treading on uncertain ground. However, I have found many dozens of cases in which one or two of the distal pores of the whole series are imperfect, or very small, obviously not functional; and frequently on the other leg the corresponding pores are altogether missing. These may be cases of retrogression, of decreasing pores ; but m y argument is of course valid for de- and increase. Only, somehow, one prefers to consider the largest numbers as representing the ultimate, newest condition. f I a m well aware that I a m treading here on dangerous ground and liable to be misunderstood. The process involved may be mysterious, but it is not mystical. "Perfection" and "law" are used for want of less equivocal turns; they are figures of speech, not concrete and absolute, but abstract and relative ideas. Few, if any, creatures are perfect in the sense that they cannot be improved. Ornithn-rhynchus may represent the acme of vertebrate perfection in the Murray River, but as a m a m m a l it is lamentably imperfect. There is a "law of chances" ; it is not a law made by the will of somebody, but a convenient expression for the average summary of facts as they result from the " nature of things." A squad of raw recruits may all make bulls' eyes, but they won't! There is onward evolution and also degeneration or devolution or regressive metamorphosis, likewise after all progressive. To exclude the latter, I used the expression " normal organism" for the sake of shortness. Those who scent teleology in |