286 



WHALES 



Figure i66. Section of 

 stomach of a Bottlenose 

 Dolphin. 

 O — oesophagus 

 F — forestomach 

 M = main stomach 

 Ps = pyloric stomach 

 P = pylorus 

 A -= ampulla of duo- 

 denum 

 {Pernkopf 1937.) 



which in big whales can hold well over 200 gallons and a ton of krill 

 (Fig. 167). Peacock (1936), who investigated the stomachs of False Killers, 

 found that their capacity varied from 2-3 gallons, and Vladykov estimated 

 the capacity of the first compartment of a Beluga's stomach at 4-8 gallons. 

 Comparing these figures with those for man (4^ pints), dogs (5^ pints), 

 pigs (14 pints), horses (4 gallons), cows (55 gallons), we find that, relatively 

 speaking, the capacity of the whale's stomach cannot be called very large 

 - nor would we expect this of a carnivorous or fish-eating animal. The 

 passage between the first and second compartments (the forestomach and 

 main stomachs) lies close to the entrance of the oesophagus, while the 

 passage to the third (the pyloric) compartment generally lies on the 

 opposite side of the main stomach. The pyloric compartment, which 

 usually resembles a bent tube, is indented to form 2-4 sub-divisions, the 

 last of which communicates with the duodenum through the very narrow 

 pylorus. Near the stomach, the duodenum of most Cetaceans expands 

 into an ampulla which has often been mistaken for yet another compart- 

 ment of the stomach. 



If we investigate the different compartments more closely, we find that 

 the first compartment is lined with hard and generally white or yellow 

 squamous but non-cornified epithelium which contains no glands and 

 hence secretes no juices. The lining of the second compartment has a very 

 much softer and somewhat velvety appearance, and is generally purple in 

 colour. Sometimes a characteristic system of reticular folds can be observed 

 in it, but at other times the folds run parallel. The appearance of the folds 

 is, in fact, determined by the extent to which the stomach is filled and 



