THE PSYCHIC DEVELOPMENT OF YOUNG ANIMALS 143 
58th day—An ox’s head, that had been boiled free 
from all flesh, was placed amongst them. They all 
attacked it eagerly, showing inexperience. 
An old dog would have acted in this way only in 
case of extreme hunger. 
Some desist and again return to the attack, but show 
that already experience has not been lost on them. 
Some of them growl when others approach. 
59th day.—The puppies are given small rib-bones 
from cooked lamb. Each carries off hig own with tail 
up; uses the paws to steady the bone; gets hold of it 
with his teeth by the end, so that he may gnaw off 
perchance some of it; growls when a fellow approaches, 
etc. All this was suggestive of the behaviour of an 
old dog. The puppies plainly recognise the nature of 
a fellow’s growl under these circumstances. 
60th day.—Temperature higher. The puppies show 
the effect of the heat both physically and psychically. 
61st day.—To-day one sheep’s head and a bone for 
each is placed in their compartment. 
In gnawing their own bone, in growling and acting 
on the defensive generally, there is considerable advance 
over the 59th day. 
They are allowed into the large yard to-day for the 
first time. They have seen this yard from the kennel 
and from their wire fence run in the middle of it. 
They mingle with the older dogs and act very much 
like them. They try to suck the dam and both the 
other bitches referred to before on the 28th, etc., days. 
They move about the yard from the first, as if 
acquainted with it, and choose the comfortably shady 
places in which to lie. By the lip-call, etc., I get them 
to follow me back to the kennel, but when inside the 
door they hesitate and soon make for the yard. When 
placed in their usual compartment in the kennel, after 
being some hours in the yard, they cry, but not long. 
