1906.] IN MEXICAN LIZARDS. 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 com- 

 posed of long rows 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 w^ant 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 G. mexicanus from 

 Ouernavaca and Cuautla [cf. p. 367), or those of G. communis 

 occidentalis from Patzcuaro, should be at such an obvious dis- 

 advantage to their gaitered brethren that these tendencies ought 

 to have been eradicated long ago. 



"Would anyone be bold enough to stijDulate a physiological 

 difference between the possession of 3 oi- 4 supraoculars ? Fine, 

 instead of coarse, granulation prevails in the skin of the depiiei- 

 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 j)Ositively 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 cZep^ei-group, except in those old-fashioned individuals, 

 about 10 per cent, with I'ather. 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 inheiitance of acquired characters. 



* Here we are treading on uncertain ground. However, I have found many 

 dozens of cases in whicli one or two of the distal pores of the whole series are 

 imperfect, or verj' 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 my argument is of course valid for de- and increase. Onlj', 

 somehow, one prefers to consider the largest numbers as representing the ultimate, 

 newest condition. 



t I am well aware that I am 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 ; thej- 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. Ornitlio- 

 rhynchus may represent the acme of vertebrate perfection in the Murraj^ River, but 

 as a mammal 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 meta- 

 morphosis, likewise after all progressive. To exclude the latter, I used the expression 

 " normal organism " for the sake of shortness. Those who scent teleology in 



