122 The Carntvora. 
which he perceived, but neglected in favour of that which 
he was intent on following. It must, indeed, be a marvellous 
faculty than can thus entertain in the sensorium a succession 
of varied perceptions and, at the same time, take account 
only of the particular impression it is desired to retain as 
associated with the presence of some individual man. It 
would seem that every human being has some special odour 
proper to himself, and distinct from that by which the dog 
recognises the genus homo in general, and distinguishes man 
from any other animal and from birds. We could never 
have known this but for the behaviour of our dogs when 
seeking their masters. ‘Further, I have reason to believe 
that they know by smell—i.e, can recall to memory the 
identity of people with whom they are familiar without 
seeing them at the moment. Reference will be made to this 
presently. 
Some naturalists have supposed that the man is traced by 
the dog by reason of some peculiarity in the leather of his 
boots. That explanation does not agree with what my experi- 
ments—so far as they go—indicate. In the first place, my 
dogs, have hunted me, at least, on grass, with more confi- 
dence and certainty when I walked barefooted than other- 
wise. New slippers and boots, which I have tried, puzzled 
them all, and one of them would take no notice whatever 
of my trail when I was shod in any kind of new foot cover- 
ing; though even new boots did not prevent Carlo I. from 
making out the trail with some difficulty while quite fresh. 
One summer morning, being with a friend in a large park, 
I suggested that we should change boots, and that he should 
cover the dog’s eyes, and presently let him go in search of 
me. It was a complete failure. For the first few yards (as 
he told me), there seemed to be a trace of me in the air, 
and the dog kept on the track, but soon became uncertain, 
and finally gave up the quest. On another occasion, I rubbed 
my bare feet with paraffin oil, and walked very leisurely 
across a lawn for a distance of, perhaps, a hundred yards. 
