626 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



uine of this planktouic mass thus lieapcd up is often ten or many times 

 greater than that in the immediately adjacent parts of the sea. On 

 the contrary, the i)hiiiktoni(; mass is extraoidinaiily poor in pelagic ani- 

 mals and plants, where by the emptying of great floods a rpiautity of 

 fresh water is brought into the sea and its saltness diminished. Johan- 

 nes Miiller pointed out how very much the result of pelagic fishery 

 was influenced therei)y. Again, on the other hand, the rivers day by 

 day bring into the sea a quantity of organic substances which serve as 

 food for the benthonic organisms, and since the benthos again stands in 

 manifold reciprocal relation to tlie plankton, since the meroplanktonic 

 animals (like the medusre, the pelagic larva) of worms," echinoderras, 

 etc.) are the means of a considerable interchiiiige between the two, so 

 is it easily understood how the distribution of the holoplanktonic ani- 

 mals is also influenced thereby and how irregular becomes the com- 

 position of the plankton. 



Zoocurrents, or planMonie streams. — Among the most noteworthy and 

 important phenomena of marine biology is the great accumulation of 

 swimming bodies which form long and narrow bands of thickened 

 plankton. All naturalists who have Avorked at the seashore for a long 

 period and have followed the irregular appearance of the pelagic organ- 

 isms know these j)eculiar streams, which the Italian fishermen call by 

 the name " correnti." Carl Vogt, in 184S, pointed out their great impor- 

 tance for pelagic fishery (17, p. 303). For their scientific designation 

 and their distinction from the other marine currents I propose the term 

 Zoocurrents or Zoorema* 



The pelagic animals and plants are so luimerous and so closely packed 

 in these zoiicurreuts as to resemble somewhat the human popuhition in 

 the busieststreet of a great commercial city. But millions and millions 

 of small creatures from all the above-mentioned groups of planktonic 

 organisms are crowded confusedly together, and furnish a spectacle of 

 whose charm a conception can be formed only by seeing it. If one 

 directly scoops up a portion of this motley crowd with a tumbler, not 

 infrequently "the greater part of the contents of the glass (an actual 

 living animal broth) is composed of the volume of animals, the smaller 

 of the volume of water" (3, p. 171). From a distance these "crowded 

 sea-animal streets'' are usually discernible from the smoothness which 

 the surface of the sea presents, while close beside it the surface is more 

 or less rippled. Often one can follow such an " oil-like animal stream," 

 which usually has a breadth of 5 to 10 meters, for more than a kilometer 

 without finding any diminution of the thick crowd of animals in it, while 

 on both sides of it, right and left, the sea is almost vacant, or shows 

 only a few scattered stragglers. At Messina, as at Lanzarote, the phe- 

 nomena of the zoocurrents were especially x)ronounced. My companion 



*Rema (used hi Messiua) is from the Greek pn'ua = current; comp. 3, n. 172 note. 



