COxMPARATIVE ANATOMY 33 



Most herbivorous mammals, e.g., Sheep, Horse, 



Elephant, 

 Some prhnates, e.g., the White-handed Gibbon 

 (Hylohates Lar), and the Orang-outang {Shnia 

 Satyrus), 

 The single caecTum is relatively largest of all in the 

 rodents, e.g., the Rabbit (Lepus Cuniculus), 



Tyj)e C. — In addition to demarcation of the junction, 

 the proximal part of the large intestine presents bi- 

 lateral ca?ca.* 



These are present in a few mammals : — 



Some xlrmadillos, e.g., Dasypus Sexcintus and 



Clainydophorus, 

 The Little Anteater (Cyclothurus Didactylus). 

 The Manatee (Manatus A'inericanus) presents a bifid 

 c«cum. 

 The bilateral type of csecum is almost constant in 

 birds. The Heron is an exception. They are however 

 very small indeed in the Wedge-tailed Eagle (Aquila 

 Aitdax) and the Lyre Bird (Menura Victoria), Gener- 

 ally speaking the caeca are short in carnivorous birds, 

 for example, the Crow (Corvus Corone), and much 

 longer in herbivorous ones. Long caeca occur in : — 

 The Ostrich (Struthio), 

 The Pheasant (Phasianus). 

 The Duck (Anas), 

 The Goose (Anser), 

 The Swan (Cygnus), 

 The Peafowl (Pavo), 

 The Bustard (Otis), and others. 

 The proximal part of the large intestine nearly always 

 contains subepithelial lymphoid tissue at any rate in 

 birds and mammals. Thus it is foundt in the bilateral 



* A curious animal, the Hyrax, shows both a juxta-ileocaecal caecum 

 and also a pair of more distant caeca. But this is quite exceptional. 



t I have sectioned the rectal gland of the Do2:fish and the pyloric 

 ca'ca of other fishes. These, however, do not exhibit lymphoid 

 tissue. 



c 



