42 INTESTINE AND DIET OF REPTILES. 



crocodiles — the differentiation of the muscular and py- 

 loric regions is perhaps more pronounced than in other forms. 

 It may thus be assumed tliat tlie arrangement of the diiFe- 

 rent regions of the ventricle as it is foiind in the crocodiles 

 is a specialization of a condition that already was present 

 in the common ancestors of lizards and crocodiles. 



In most lizards the mucosa of the small intestine is lon- 

 gitudinally plicated. Such an arrangement increases consi- 

 derably the degree in which the intestine can be dilated, 

 which of conrse is of iraportance as the animals have practi- 

 cally no power of masticating the prey, and the crushing or 

 breaking power of the ventricle is rather limited. An in- 

 vestigation of the small intestine reveals al so very of ten 

 how it is strongly distended by food-material, it may be 

 elytra or other chitinous parts of insects, berries, seeds or 

 chunks of other vegetable raatter. In Tupinambis and Va- 

 ranus the pliccfi of the small intestine are more or less trans- 

 versally arranged which might stånd in connection with 

 their (partly or entirely) predatory habit. 



The leaf-like villi of Ophisaurus are also transversally 

 arranged and the intestine is comparatively wide. 



The comparative measnrements recorded in the table 

 (p. 34) indicate the relation between the length of head and 

 body (distance from snout to vent) and the length of the 

 small and large intestine respectively in snch a vray that 

 the length of the latter organs is expressed in percentages 

 of the former measnrement. The non-conformity in the ge- 

 neral shape of some short and broad, or long and slender 

 lizards cause that the relative measnrements, expressed in 

 such a manner as is stated above, are not directly com- 

 parable in all instances, but if dne regard is paid to this 

 it does not seem to involve too great uncertainty to draw 

 some conclusions of general acceptabilit3^ If we then first 

 pay attention to the insectivorous Geckonids which have 

 almost the same general shape we shall see that they also 

 agree pretty well with regard to their relative measnrements 

 of the intestine. The average length of the small intestine 

 is about 111 ^ of the standard measnrement and that of the 

 large intestine 30 %. The deviations from these figures are 

 not great and in some cases as in Ftychozoon a short small 

 intestine is compensated by a rather long large intestine or 



