0>68 PHILOSOPHY" OF ZOOLOGY. 



food, some birds, as the common duck, cover the eggs care- 

 fully with down and straw to preserve their warmth, and 

 probably likewise to conceal them from foes. When the eggs 

 are hatched, the old birds for some time continue to sit at in- 

 tervals on the young brood, to preserve their temperature. 



Among the niammiferous animals, the same instinctive 

 carefulness, when requisite to keep their young offspring 

 warm, is equally apparent. Some make a common bed, as 

 the sow, and permit the young ones to lie in her bosom. 

 The rabbit, on the other hand, covers her young ones at the 

 first with hair, and closes up the entrance to her nest, to 

 prevent the circulation of cold air. 



d. In each species keeping its own offspring in a suit- 

 able state of cleanliness. The circumstances attending the 

 birth of many animals, call for the immediate exertion of 

 the parent to remove those things which at the time or af- 

 terwards would injure or incommode. Thus, in the nests 

 of birds the fragments of the eggshells, if permitted to 

 remain, would bruise and otherwise injure the young. 

 These, however, the parent birds take up in their bill, 

 and remove them to a distance. In the case of young 

 quadrupeds, the rapidity of evaporation from their moist 

 surface, immediately after birth, would prove injurious to 

 them. But the mother, as may be seen in the case of the 

 sheep, cow, or mare, forgetting the pains of parturition, be- 

 gins to lick the hair and make it dry. 



But these are not all the evils which the instinctive 

 power we are now considering prompts the parents of ani- 

 mals to remove. Before the young birds are capable of 

 voiding their excrement over the margin of the nest, the 

 old ones convey away the mutings, which are at first cover- 

 ed with a pellicle, in their bills, and drop them at a distance 

 from their nest. With rabbits and other quadrupeds, 

 whose young dwell in holes, and are born blind, without 



