MARINE BIOLOGICAL STATION AT PORT ERIN. 17 



In writing of the masses of weed in the Sargasso Sea. 

 he says,* " The floating islands have inhabitants peculiar 

 to them, and I know of no more perfect example of protective 

 resemblance than that which is shown in the gulf-weed fauna. 

 Animals drifting about on the surface of the sea with such 

 scanty cover as the single broken layer of the sea-weed, must 

 be exposed to exceptional danger from the sharp-eyed sea-birds 

 hovering above them, and from the hungry fishes searching 

 for prey beneath ; but one and all of these creatures imitate 

 in such an extraordinary way. both in form and colouring. 

 their floating habitat, and consequently one another, that 

 we can well imagine their deceiving both the birds and the 



fishes A little short-tailed crab (Nautilograpsus 



minutus) swarms on the weed and on every floating object, 

 and it is odd to see how the little creature usually corresponds 

 in colour with whatever it may happen to inhabit. These 

 gulf- weed animals, fishes, mollusca. and crabs, do not simply 

 imitate the colours of the gulf-weed : to do so would be to 

 produce suspicious patches of continuous olive : they arp. 

 all blotched over with bright opaque white, the blotches 

 generally rounded, sometimes irregular, but at a little distance 

 absolutely imdistinguishable from the patches of Membranvpora 

 on the weed." 



On one occasion he describes (p. 147) the loss of a great 

 catch, when trawling at a depth of 2,350 fathoms in the South 

 Atlantic. " The trawl was lowered, and on heaving in it came 

 up apparently with a heavy weight, the accumulators being 

 stretched to the utmost. It was a long and weary wind-in 

 on account of the continued strain ; at length it came close 

 to the surface, and we could see the distended net through 

 the water ; when, just as it was leaving the water, and so 

 greatly increasing its weight, the swivel between the dredge- 

 rope and the chain gave way, and the trawl with its unknown 

 * Atlantic, Vol. II. p. 10. 



