620 REPCRT OF COMMISSIONER OF FISH AND FISHERIES. 
ever studied, those which the Challenger brought from her stations 
262-280. My astonishment was great when I first saw these planktonic 
masses, in the autumn of 1876; but it grew boundless when a year 
later I studied preparations taken from them and found in them hun- 
dreds of new species of pelagie animals. 
The wonderfully rich Radiolaria ooze which the Challenger brought 
up at the central Pacifie stations 263-274 (from depths of 2,000 to 3,000 
fathoms) is only the siliceous remains of that planktonic mass, from which 
all organic constituents have vanished and the caleareous shells for the 
most part dissolved by the carbonie acid of the deep currents.* The 
numerous surface preparations which Murray finished upon the spot 
on this remarkable voyage of planktonic discovery through the central 
Pacific, and mounted in Canada balsam, are absolutely the richest plank- 
ton preparations which I have ever studied, especially those of stations 
266-274, between 11° N. lat. and 7° S. lat. The richest of all stations 
is 271, lying almost under the equator (0° 33/5. lat., 152° 56’ W. long.). 
I have since shown these preparations for microscopical studies to many 
colleagues and friends, and they have always expressed the liveliest 
astonishment over the new “ wonder-world ” concealed in them. They 
are jokingly called the “‘mira-preparations” (comp. 4, §§ 228-235). 
The wonderful plankton wealth of the tropical Pacifie is as well 
established by the manifold observations of Chierchia: “The quantity 
and quality of the organisms which inhabit the tropical regions of the sea 
surpass all conception” (8, p. 75). Ineconceivable quantities of pelagic 
animals of all groups were seen in the middle of the tropical Pacifie, 
between Callao and Hawaii, between Honolulu and Hongkong, not 
only at the surface, but in the most various depths up to 4,000 meters. 
The quantity of deep-sea siphonophores was here so enormous that the 
sounding lead was never drawn up without its being surrounded with 
torn-off tentacles (p. 85). During the forty days’ voyage from Peru to 
Hawaii-the pelagic fishery at the surface as well as in the depths 
brought to light “such a quantity of different organisms that it must 
seem almost impossible to one who did not follow the work with his own 
eyes” (8, p. 88). Similarly, in the Chinese sea and in the Sunda Archi- 
pelago immense masses of plankton were encountered. : 
It is my intention here to bring together the most general impres- 
sions of the relative planktonic wealth of the various oceanic regions, 
which I have gained from a comparative study of many thousand 
planktonic preparations. The pelagic fauna and flora of the tropical 
zone is richer in different forms of life than that of the temperate zone, 
and this again is richer than that of the cold zone of the ocean. This 
is true of the oceanic as well as of the neritic plankton. Everywhere 
the neritic plankton is more varied than the oceanic. The wealth of 
species) contained in the “ Radiolarian collection” (1890) above mentioned. The8 
richest of these (Nos, 20-27) belong to the tropical central Pacific (stations 265-274), 
