62 
Strait of Basilan, near Zamboanga, my attention was attracted by 
a very conspicuous black thing moving about in the shallow water. i 
On coming Close to it I saw, it was a mass of small fishes, black, 
with two longitudinal white stripes on the sides of the back. They 
swam very closely together, making thus a large ball; by the constant 
movement of the small fishes among one another the ball seem- 
ingly rolled along over the corals, making an exceedingly con- 
spicuous object. It was quite easy to catch nearly all of them with 
a single stroke of 
a handnet. In order 
to preserve some 
specimens of them 
I started to take 
them with the hand 
from the net. The 
first one I touched 
stuck to my fingers, 
producing a most 
intense pain, and 
on trying to get it 
off, I had it hang- 
Fig. 2. Plotosus anguillaris Bloch. Natural size. ing in my other 
fingers. It was ex- 
ceedingly painful, the pain lasting quite a while after I had suc- 
ceded in getting it off. After this experience I avoided, of course, 
most carefully to touch any specimen of this fish, and when I had 
succeded in getting some of them preserved I kept carefully away 
from these black, rolling balls. 
That this is a case of warning coloration cannot be doubted; but 
it is not warning coloration alone. On account of the small size 
of the fish the coloration, though very conspicuous in itself, would 
hardly be of any use for the purpose; but the habit of these small 
fishes to swim very close together in great numbers — by the 
hundreds, I am sure, without having counted them directly ; I should 
well beware of doing that — combined with their conspicuous 
coloration, certainly produces the required result to warn against 
touching them. No predacious fish or bird or other would-be enemy, 
man included, will venture to touch them more than once. 
