120 EDWARD L. RICE 
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1. INTRODUCTION 
Since the publication, in 1900, of Gaupp’s classic paper on the 
chondrocranium of Lacerta there have been great additions to 
the accurate and detailed knowledge of the embryology of the 
vertebrate skull. But the data for comparative study are still 
inadequate, and many theoretical questions are still dependent 
for their satisfactory settlement upon the investigation of a 
more extensive series of species. 
Especially is it through the investigation of closely related 
forms that the essential and general can be freed from the inci- 
dental and individual and built up into a firm foundation for 
legitimate theorizing. Thus Eumeces has a special claim for 
consideration because of its comparatively close relationship to 
Lacerta, which has become the standard for comparison, thanks 
to the masterly work of Gaupp. 
The similarities and contrasts of Eumeces and Lacerta may 
be emphasized most conveniently by a strictly comparative treat- 
ment based upon Gaupp’s paper (’00). For the most part, 
both the order of treatment (except for the division of Gaupp’s 
paper into two parts, descriptive and theoretical, respectively) 
and the terminology of Gaupp are adopted here. 
Partial results of this study have been published in the form 
of brief preliminary notes (’11, 714); here they appear in more 
complete form. In the present paper the history is followed 
only to the stage of maximum development of the chondro- 
cranium; the fate of the cartilages in later embryos and in the 
adult skull and the development of the bones, aside from merely 
incidental references, are left for later treatment. 
The earlier literature on skull development has been so admi- 
rably summarized by Gaupp in Hertwig’s ‘Handbuch’ (’05 b) 
that any further extensive review would be superfluous. 
