12 



ME. G. A. BOULEXGER ON LIZAEDS 



Gadow*, but which have been opposed by Mehely f , the .primitive type of Lizard is 

 striated, the original light and dark streaks breaking up into spots, and these spots 

 further becoming confluent into transverse lines — tend to form cross-bands, whilst, 

 in another direction, the markings disappear altogether; in the course of the changes 

 — ontogenetic or phylogenetic, as the case may be — the pattern of the posterior part 

 of the body anticipates the evolution of that of the anterior part. Text-fig. 4 makes 

 these principles clear. 



Text-fi<ruro 4. 





r*-*) 



Variatioa of markings in Cnemklophorus, after Cope. 

 (A-F, C. tessellatus ; G-L. C. gularis.) 



In most cases the young show a more primitive pattern than the adult, but never 

 the reverse, as would be the case if Mehely's view were correct. The more advanced 

 pattern, on the other hand, may appear at birth, and forms in which this is the case 

 arc therefore to be regarded as the most remote from the primitive type. 



The ancestral type of Lacerta I conceive to have had five + wliite streaks, separated 



* Proc. 11. See. Ixxii. 1903, p. 109, pis. iii.-v., and Proe. Zool. Soc. 1900, p. 277, tigs, 

 t Ann. Mus. Hung. v. 1907, pp. 84 &, 477. 



X Six may be postulated for tlic Lacertidu;, to explain the markings in other genera, such as Lalaslia and 

 Acanthodactylus. 



