MENTAL POWERS OF ANIMALS. 369 



been partially completed, the site is, for some reason or another, 

 found insecure, and a fresh one chosen ; the materials from the 

 old nest being utilized freely for the new one. I have known of 

 an instance in which a pair of birds shifted their nest three 

 times in quick succession to various parts of a bush, but could 

 not ascertain the reason of this. I examined the rejected sites 

 most minutely with a powerful magnifying-glass, but not an insect 

 of any kind was visible, and the rejected sites appeared to be 

 better sheltered from rain and wind than the one chosen last. 

 There must, however, have been some defect, and, in justice to 

 the wisdom of the birds, I must add that they successfully reared 

 their young. 



The cleaning of the nests by most Passerine birds is purely 

 an instinctive action; but to realize fully the dangers which 

 would ensue from insanitary conditions, if the excreta of the 

 young were not carried away by the parent birds, one has only 

 to keep, for a few hours, a nest full of young Tits or Magpies. 

 In some species both parents help in cleaning the nest ; while 

 in others I have noticed that this task is relegated only to the 

 hen. Of course the pains taken by the old birds to drop the 

 excreta as far away as possible from the nest have the obvious 

 object of concealing all traces of their young from likely enemies. 



Faint traces of what may be called forethought are sometimes 

 noticeable in dogs and birds. One of my terriers, when not 

 hungry, has a habit of concealing bones in holes in the ground, 

 and then covering them over with some mud. Whether she 

 ever remembers these places afterwards, when necessity arises, 

 and brings out the hidden treasures, I have been unable to 

 ascertain. 



Various species of Magpies in confinement also exhibit this 

 habit of hiding scraps of food in nooks and corners of their cages. 



We have often heard of dogs, which have been brought up 

 with cats, imitating the latter in some of their habits; but at 

 present I have a dog which has never in all her life been 

 privileged to associate with any members of the cat species, and 

 yet some of its actions are distinctly feline in character. For 

 instance, it has a habit of playing with a wounded bird, or half- 

 dead mouse, just as a cat does. And again, it licks its paws, 

 and frequently sits with its front legs bent inwards. When 



