Hunting Back Trail. 123 
The dog was unable to track me. A few days after this I 
rolled across the lawn the same distance and he ran on the 
trail with confidence. 
Presuming from these trials that every part of my 
body left some trace of the special odour belonging to me, 
and associated in the dog’s mind with my individuality, I 
determined to extend them whenever a favourable oppor- 
tunity presented itself. But unfortunately the series I 
had planned could not be carried out systematically, for he 
became languid and indisposed for exercise, and within 
two or three months died of aneurism on the aorta. However, 
I ascertained that he was able to track me with great ease 
riding on a bicycle and trailing my coat on the ground by a 
string, but with more difficulty when I used a felt hat or one 
of my boots in the same way. 
Hunting on a back scent is an accomplishment which seems 
to imply much discrimination. It would be an unwarrantable 
supposition to entertain that few dogs are capable of this, 
but, with a considerable acquaintance among good retrievers, 
I have seen only two—Carlo I. and his grandson—perform 
this feat thoroughly well; though, probably, any well trained 
retriever would prove equally expert if the necessity pre- 
sented itself to his mind. 
I am bound to confess that I did not think of it as even 
possible, until Carlo I. showed quite unexpectedly what he 
could do. In stalking a kangaroo for some time in a dense 
scrub with no result, my powder-flask fell unnoticed out 
of my breast pocket. Valuing the article as the gift of an 
old friend, I determined to make an effort to find it, though 
the difficulty of retracing my steps through thick wattle 
bushes and interlaced creeping plants appeared almost in- 
superable, especially as there was nothing in the way of 
a landmark, where the stem of each tree was exactly like 
every other, and the few open spaces I had crossed were 
covered with a uniform growth of ferns. For some minutes 
I wandered back as nearly as I could in the right direction 
