434 
ANIMAL INTELLIGENCE. 
With reference to this case I wrote to ‘Nature’ as 
follows. The friend to whom I allude was the late Dr. 
Brydon, C.B. (the 6 last man 5 of the Afghan expedition 
of 1841), whom I knew intimately for several years, and 
always found his observations on animals to be trust 
worthy : — - 
In response to the appeal which closes Mr. Buck’s interest - 
ing letter ( 4 Nature,’ vol. viif. p. 302), the following instance of 
‘ collective instinct ’ exhibited by an animal closely allied to the 
wolf, viz., the Indian jackal, deserves to be recorded. It was 
communicated to me by a gentleman (since deceased) on whose 
veracity I can depend. This gentleman was waiting in a tree 
to shoot tigers as they came to drink at a large lake (I forget 
the district), skirted by a dense jungle, when about midnight 
a large axis deer emerged from the latter and went to the 
waters edge. Then it stopped and sniffed the air* in the direc- 
tion of the jungle, as if suspecting the presence of an enemy ; 
apparently satisfied, however, it began to drink, and continued 
to do so for a most inordinate length of time. When literally 
swollen with water it turned to go into the jungle, but was 
met on its extreme margin by a jackal, which, with a sharp 
yelp, turned it again into the open. The deer seemed much 
startled, and ran along the shore for some distance, when it 
again attempted to enter the jungle, but. was again met and 
driven back in the same manner. The night being calm, my 
friend could hear this process being repeated time after time — 
the yelps becoming successively fainter and fainter in the dis- 
tance, until they became wholly inaudible. The stratagem thus 
employed was sufficiently evident. The lake having a long 
narrow shore intervening between it and the jungle, the jackals 
formed themselves in line along it while concealed within the 
extreme edge of the cover, and waited until the deer was water- 
logged. Their prey, being thus rendered heavy and short- 
winded, would fall an easy victim if induced to run sufficiently 
far, i.e ., if prevented from entering the jungle. It was, of 
course, impossible to estimate the number of jackals engaged in 
this hunt, for it is not impossible that as soon as one had done 
duty at one place, it outran the deer to await it in another. 
A native servant who accompanied my friend told him that 
this was a stratagem habitually employed by the jackals in that 
place, and that they hunted in sufficient numbers 4 to leave 
nothing but the bones.’ As it is a stratagem which could only 
be effectual under the peculiar local conditions described, it 
