XX. On the Hereditary Instinctive Propensities of Animals. By Thomas Andrew 
Knight,, Esq. F.R.S. President of the Horticultural Society , fyc. fyc. 
Received May 15, — Read May 25, 1837. 
In a communication which I had the honour many years ago to address to this So- 
ciety upon the Economy of Bees, I gave an opinion that families of those insects, in 
common with those of every species of domesticated animal, are to a greater or less 
extent governed by a power which I have there called “ an instinctive hereditary pro- 
pensity that is, by an irresistible propensity to do that which their predecessors of 
the same family have been taught or constrained to do, through many successive ge- 
nerations. In that communication I stated that a young Terrier, whose parents had 
been much employed in destroying Polecats, and a young Springing Spaniel, whose 
ancestry through many generations had been employed in finding Woodcocks, were 
reared together as companions, the Terrier not having been permitted to see a Polecat, 
or any other animal of similar character, and the Spaniel having been prevented seeing 
a Woodcock, or other kind of game ; and that the Terrier evinced, as soon as it per- 
ceived the scent of the Polecat, very violent anger ; and as soon as it saw the Polecat 
attacked it with the same degree of fury as its parents would have done. The young 
Spaniel, on the contrary, looked on with indifference ; but it pursued the first Wood- 
cock which it ever saw with joy and exultation, of which its companion, the Terrier, 
did not in any degree partake. 
I had at that period made a great many analogous experiments, and I have subse- 
quently made a considerable number, chiefly upon one variety of dog, namely, that 
which is generally used in search of Woodcocks, and is usually called the Springing 
Spaniel. These experiments were commenced nearly sixty years ago, and occupied a 
good deal of my attention during more than twenty years, and to a less extent nearly 
to the present time ; and as it does not appear to me probable that any person is now 
likely to investigate this subject as laboriously, or through so long a period, I have 
been induced to believe that the facts which I am prepared to communicate may be 
thought to deserve to be recorded in the Transactions of this Society. 
At the period in which my experiments commenced, well-bred and well-taught 
Springing Spaniels were abundant, and I readily obtained possession of as many as I 
wanted. I had at first no other object in view than that of obtaining dogs of great 
excellence; but within a very short time some facts came under my observation 
which very strongly arrested my attention. In several instances young and wholly 
inexperienced dogs appeared very nearly as expert in finding Woodcocks as their ex- 
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