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ANIMAL INTELLIGENCE 
angler. We must also allude to the Chelmon to stratus , 
which shoots its prey by means of a drop of water projected 
from the mouth with considerable force and unerring aim. 
The mark thus shot at is always some small object, such 
as a fly, at rest above the surface of the water, so that 
when suddenly hit it falls into the water . 1 This remark- 
able instinct can only, I think, have originated as a 
primordially intentional adjustment, and as such shows a 
high degree of intelligence on the part of these fishes’ an- 
cestors. Moreover, the wonderful co-ordination of sight 
and muscular movements required to judge the distance, 
to make due allowance for refraction, and to aim correctly, 
shows that the existing representatives are not unworthy 
of their ancestors. 
Several species of fish in different parts of the world 
have the habit of quitting pools which are about to dry 
up, and taking excursions across country in search of more 
abundant water. Eels have this habit, and perform their 
migrations by night. Dr. Hancock, in the 6 Zoological 
Journal,’ gives an account of a species of Boras , the indi- 
viduals of which are about a foot in length, and travel by 
night in large shoals, or 6 droves,’ when thus searching for 
water. A strong serrated arm constitutes the first ray of 
the pectoral fin; and, using this as a kind of foot, the animal 
pushes itself forward by means of its tail, thus moving 
nearly as fast as a man can walk. Another migrating fish 
(ffydrargzra) was found by thousands in the fresh waters 
of Carolina by Bose. It travels by leaps, and, according 
to Bose, always directs itself towards the nearest water, 
although he purposely placed them so that they could not 
see it. 
But perhaps the strangest among this class of habits 
is that of the climbing fish, first discovered by Daldorff 
in Tranquebar ; for this animal not only creeps over 
land, but even climbs the fan palm in search of certain 
Crustacea which form its food. In climbing it uses 
its open gill-covers as hands wherewith to suspend it- 
self, while it deflects its tail laterally upwards so as 
to bring to bear upon the bark certain little spines with 
1 Sec ‘ On the Jaculator-Fish,’ by Schlosscr, Phil. Trans., 1764. 
