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A CONTEIBUTION TO OUE KNOWLEDGE OF THE 
ANATOMY OF CHAMAELEONS. 
By Paul A. Methuen, M.A. (Oxon), and John Hewitt, B.A. (Cantab). 
(Eeceived August 24, 1913. Eead September 17th). 
Introduction. 
In this paper we record the results of some investigations which com- 
menced with the examination of the lungs of the various species of 
Chamaeleon found in South Africa, but which eventually led to an attempt 
to determine the morphological position of the various forms in general. 
The preliminary examination of one character alone furnished data 
which induced us to make a critical survey of various structural char- 
acters ; and it soon became apparent that the group which included the 
viviparous C. pumihis and its allies was in several respects more 
generalized than the group of oviparous Chamaeleons, namely, G. dilepis 
and allies, but that to what extent these two groups might be sharply 
separated and how far the simplicity of structure in the pumihis sec- 
tion might be primitive or secondary could only be ascertained by an 
examination of all the main types of the family. A survey as comprehen- 
sive as this has not been possible, but sufficient material from Madagascar 
(as recorded in Ann. Trans. Mus., vol. iii., 1913, p. 190) and from South 
Africa has been available to enable us to place the more important groups 
of the family in their respective positions with regard to structure, and to 
point out the primitive forms with fair degree of probability. 
This account is therefore not intended to deal exhaustively with any 
morphological character herein considered, but merely to compare the 
several structures concerned as they are found in the various species. 
The Lungs. 
The peculiar features of the lungs of the common Chamaeleon 
(G. vulgaris) have often been figured and briefly described in the various 
text-books of comparative anatomy ; but as was pointed out long ago by 
Cuvier, and recently emphasized by Mr. F. E. Beddard (P.Z.S. 1907, 
p. 35), such features are not found in all species, and it has been shown 
that the small Cape Chamaeleon {C . pumihis) possesses lungs which are in 
no way anomalous amongst Lacertilia. Beddard' s paper includes an 
excellent account of the lungs of the latter species and of several others. 
If the lungs of Ghamaeleoii vulgaris be examined, it will be seen that 
the organ is produced into a number of elongated sacs or diverticula which 
in structure differ from the lung itself in that these processes are not sup- 
plied with a reticulum of blood-vessels. The function of these diverticula 
8 
HmA 1914 
