CONDITIONS OF LIFE 247 



with the large and curiously shaped jelly-fishes known as 

 Portuguese Men-of-war. Here we have a type of partnership in 

 which the fish definitely enjoys protection from its enemies, 

 but confers no benefit on its host. It was formerly believed 

 that, in spite of the fact that jelly-fishes seized and devoured 

 other small fishes, they did no harm to those that normally 

 sought shelter beneath them; but it is more than probable that 

 these fishes sometimes fall victims to the paralysing stinging- 

 cells, and that they owe their comparative immunity to their 

 agility in avoiding the tentacles when entering or leaving the 

 sanctuary. Dr. Beebe gives a graphic description of a shoal 

 of jelly-fishes or "Quads," of which roughly one in every four 

 had one or more little Carangid fishes or Bumpers as passengers : 

 small quads with half-inch fish, and large ones, perhaps four 

 inches across, with several two-inch fish or about a dozen of 

 the smaller size. He watched the little fishes manoeuvring for 

 several moments before darting between the tentacles, and 

 noticed that they were not infrequently killed while entering 

 their retreat. "The Quad," he writes, "probably does not 

 even know of the fishes' presence until one of them ineptly 

 bumps against the hair-trigger of its nettle batteries, and 

 aflfords it a hearty meal. . . . When from a Quad measuring 

 two by four inches, there pours forth no fewer than a dozen 

 healthy little fish, these must have been packed together like 

 sardines in a tin." 



The Rudder-fish [Lirus) of the North Atlantic, another 

 member of the same tribe, has the curious habit of accompanying 

 floating logs or planks, or of taking up its abode within floating 

 barrels or broken boxes, a habit which has earned for the 

 species the name of "wreck-fish." A story is related of a shoal 

 of these fishes that accompanied a floating log which was 

 finally washed ashore at the Aran Islands off the west coast of 

 Ireland, to the great consternation of the inhabitants, who were 

 convinced that these fishes, with which they were quite 

 unfamiliar, were sheogues or fairies. They ran away thoroughly 

 frightened, and one old man, who was bold enough to carry 

 some of the fishes home with him, was not permitted to take 

 them into his house. The attraction to the fishes is the barnacles 

 and other minute and succulent forms of animal life with which 

 derelict timber is almost invariably covered. 



In the association between fishes and jelly-fishes described 

 above the benefit is all on the side of the former, and a number 

 of other examples of such a one-sided partnership are known. 



