184 THE RANGE OF ANIMAL DIET 



become largely a vegetable feeder, greatly to the advan- 

 tage of his health in confinement, and, by the substi- 

 tution of the uniform * dog-biscuit ' for table-scraps or 

 meat, have given him a mixture of meal and dates 

 which is as agreeable to crack as a bone. Among the 

 more highly organized creatures ' single-food ' animals 

 are scarce and growing scarcer. There is evidence that 

 the mute swan once fed almost entirely on sub-aquatic 

 grasses. At Abbotsbury, when the ice destroyed the 

 grass growing at the bottom of the lagoon, the half- 

 wild swans refused to touch any other food, and starved 

 in hundreds. Now they have learnt to eat grain, just 

 as the Thames swans have learnt to eat bread and the 

 grain which falls from barges. Probably the Abbots- 

 bury swans were the last of their species in England 

 which were ' single-food ' animals, and with their conver- 

 sion the extension of the range of diet is completed. 



Reindeer feed almost entirely on mosses and lichen. 

 It is still matter for doubt whether they can be 

 acclimatized in this country, though experiments are 

 being made to that end. If they cannot, an extension 

 of the species, even though in domestication, will be 

 prevented by their limited food-range. The moose 

 feeds entirely on the bark and twigs of trees. But this 

 is partly due to the height of its forelegs and the short- 

 ness of its neck, which make it almost impossible for it 

 to graze. When fed from a manger the moose takes 



