NO. 1861 THE ARCHUR-FISH AND ITS FEATS — GILL 283 



the captor. Its companions, like it, dart towards the victim and this 

 naturally becomes the prize of the most adroit or lucky one. 



Discrimination and selection were exercised in the choice of in- 

 sects. The common house-fly was distasteful and only taken, it was 

 thought, when the demands of hunger could not be otherwise ap- 

 peased. Ants were the chosen food, and small black ants were pre- 

 ferred to the red ones, presumably because the former were less 

 penetrated by formic acid than the latter. (Zolotnitsky, 76.) 



Considerable ingenuity is sometimes manifested in the attempt to 

 secure food. On one occasion a larva (bloodworm) of a midge 

 (Chironoimis) was thrown by Zolotnitsky into the aquarium, but 

 it lodged by the side and an Archer tried several times in vain to 

 secure it, merely pushing it closer against the glass with its project- 

 ing lower jaw; at length, it backed a little and blew on the larva, 

 so that the latter was sent toward the middle, and then the Archer 

 readily captured it. The experiment was twice repeated and the fish 

 applied the same strategy to the capture of both larvae. 



Zolotnitsky was very much impressed with the apparent reason 

 which the fish applied. He thought, too, that^the old archers could 

 and did measure and proportion the distance and the force used 

 in projecting the drops. The old fishes directed their efiforts so 

 successfully that the insects aimed at always fell within reach, but 

 the young ones sometimes used such force as to shoot the flies so 

 that they fell outside of the aquarium. 



Although chiefly day-feeders, the Archers are also active and may 

 feed during a bright moon-light night. One hot summer day Zolot- 

 nitsky (78) left the aquarium in the open air, and near it a lamp 

 with a great moon-like globe, which attracted a number of insects — 

 mosquitoes, moths and others ; many of these came within reach of 

 the archers' shots and the fishes became greatly excited and very 

 active, feeding to repletion. The next day, however, they were in 

 excellent condition and exhibited renewed brilliancy of colors. 



VII 



Nothing is known respecting the reproductive habits. Zolotnitsky 

 (80) believed that the temperature suitable for spawning was about 

 73° F. to 75° F. (18° R. a-f 19° R.). At such a temperature he 

 found that they were very lively and playful and would be 

 attracted by their own images reflected from the mirror-like sides 

 of the aquarium. Their play was so i)ersistcnt that they even ceased 



