56 
ANIMAL INTELLIGENCE. 
appeared. Now, three months later, the lower colony has been 
entirely abandoned. Occasionally, however, especially when 
fresh and fragrant violets have been placed on the shelf, a few 
4 prospectors 9 descend from the upper nail-hole, rarely, almost 
never, approaching the vase from which they were first driven 
away, but seeking to satisfy their desire at the tumbler. To 
turn back these stragglers and keep them out of sight for a 
number of days, sometimes for a fortnight, it is sufficient to 
kill one or two ants on the trail which they follow descending 
the wall. This I have recently done as high up as I can reach, 
three or four feet above the mantel. The moment this spot is 
reached, an ant turns abruptly and makes for home, and in a 
little while there is not an ant visible on the wall. 
In a subsequent volume of 6 Nature 5 (viii. p. 244), 
Mr. Darwin publishes another letter which he received from 
Mr. Hague upon the same subject. It seems that Mr. Mog- 
gridge suggested to Mr. Darwin that, as he and others had 
observed ants to be repelled by the mere scent of a finger 
drawn across their path, the observation of Mr. Hague 
might really resolve itself into a dislike on the part of the 
ants to cross a line over which a finger had been drawn, 
and have nothing to do with intelligent terror inspired by 
the sight of their slaughtered companions. The following 
is Mr. Hague’s reply to Mr. Darwin’s request for further 
experiments to test this point : — 
Acting on Mr. M *s suggestion, I first tried making simple 
finger-marks on their path (the mantel is of marble), and found 
just the results which he describes in his note as observed by 
himself at Mentone, that is, no marked symptoms of fear, but a 
dislike to the spot, and an effort to avoid it by going around it, 
or by turning back and only crossing it again after an interval 
of time. I then killed several ants on the path, using a smooth 
stone or piece of ivory, instead of my finger, to crush them. In 
this case the ants approaching all turned back as before, and 
with much greater exhibition of fear than when the simple 
tinger-mark was made. This I did repeatedly. The final re- 
sult was the same as obtained last winter. They persisted in 
coming for a week or two, during which I continued to kill 
them, and then they disappeared, and we have seen none since. 
J t would appear from this that while the taint of the hand u 
sufficient to turn them back, the killing of their fellows with a 
stone or other material produces the effect described in my first 
