82 ARKIV FÖR ZOOLOGI. BAND 1. 



In my previous paper 011 the intestinal canal of the 

 lizards I have already (1. c. p. 41 — 42) pointed ont the re- 

 seinblance between the structure of tlie ventricle in lizards, 

 especially Varemus, and the same in Crocodiles and that »it 

 may thns be assnmed that the arrangement of the different 

 regions of the ventricle as it is found in the crocodiles is a 

 specialization of a condition that already was present in the 

 common ancestors of lizards and crocodiles.» Af t er this re- 

 newed investigation the homology between the different regions 

 of the ventricle of lizards and crocodiles mnst be still more 

 emphasized. The mnscnlar ventricle of the lizards, especially 

 its posterior portion, corresponds to the »gizzard» of the cro- 

 codiles, and the pyloric tract between the sphincter and the 

 valve in the former corresponds to the pyloric ventricle in 

 the latter. 



This comparison may be carried still fnrther. Espe- 

 cially throngh the researches of Dr. G. Swenander* on 

 the oesophagns and ventricle of birds, it has been proved 

 that there exists a certain pyloric tract intercalary between 

 the gizzard and the dnodenum of certain birds, and I have 

 no doubt concerning the homology between that portion 

 and the pyloric tract just described from lizards and cro- 

 codiles. 



The entire length of the intestine of the specimen from 

 which the measurements of the ventricle have been pro- 

 cured above was abont 100 cm. and of that hardly more than 

 25 can be connted as the length of the large intestine. 

 The interiör of the small intestine is obliqnely plicated as 

 I have described and figur ed in my previous paper. Small 

 as well as large intetestines are rather wide. Already the 

 former is mostly 3 — 3 V 2 cm. across and the large intestine 

 is still wider. There cannot be detected any coecum by an 

 external inspection, but when the intestine is cut open there 

 is fonnd on the mesenteric side at the limit between the 

 small and large intestines a valve projecting into the lumen. 

 This valve is not very broad. Its free margin measures 

 only a little more than 2 cm., but on the colic side of 

 this valve is a pocket which extends about 2 cm. in a for- 

 ward and dorsal direction. This pocket from the colon cor- 



* Studien iiber den Bau des Schlundes und des Magens der Vögel. K. 

 Norsk. Vidensk. Selsk. Skr. 1901 N:o 6. Trondhjem 1902. 



