64 ESSAY ON CLASSIFICATION. 



mals remarkable for their peculiar structure which are 

 circumscribed within definite limits, and this localization 

 of special structures is a striking confirmation of the 

 views expressed already in another connection, that the 

 organization of animals, whatever it is, is adapted to 

 various and identical conditions of existence, and can in 

 no way be considered as originating from these condi- 

 tions. 



SECTION XII. 



SERIAL CONNECTION IN THE STRUCTURE OF ANIMALS WIDELY 

 SCATTERED UPON THE SURFACE OF OUR GLOBE. 



Ever since I have become acquainted with the reptiles 

 inhabiting different parts of the world, I have been struck 

 with a remarkable fact, not yet noticed by naturalists, as 

 fur as I know, and of which no other class exhibits such 

 striking examples. This fact is, that among Saurians, as 

 well as among Batrachians, there are families, the repre- 

 sentatives of which, though scattered all over the globe, 

 form the most natural connected series, in which every 

 link represents one particular degree of development. 

 The Scincoids, 1 among Saurians, are one of these families. 

 It contains about one hundred species, referred by Du- 

 meril and Bibron to thirty-one genera, which, in the de- 

 velopment of their organs of locomotion, exhibit most 

 remarkable combinations, as illustrated in a diagram on 

 opposite page. 



Fully to appreciate the meaning of this diagram, it 

 ought to be remembered that the animals belonging to 

 this family are considered here in two different points of 



1 For the characters of the family, COCTEAU, Etudes sur les Scincoides; 

 see DUMERIL et BIBRON, Erpetologie Paris, 1836, 4to. fig. 

 general e, vol. 5, p. 511. See also 



