5GS REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



various depths. As the most signiticaiit <ieiiei-al result Murray, in liis 

 'Treli miliary Ivei)ort" (187(5), says: 



Everywlicre wc have found a rich oij^anic life at and bchtw the surface of the 

 ocean. If living individuals are scarce at tlie surface, below it the tow net commonly 

 discloses numerous forms, even to a depth of 1,000 fathoms and more (5, p. 536). 



Ill 187"), on tlic Journey tlirou^li tlieXorth Paeifie Ocean (from Japan 

 to tlie Sancl\\i(!h Islands), the extremely important fact was established 

 that the pelagic organisms in oceanic zones of different dei)ths belong- 

 to different species; fine pelagic nets (or tow nets) "on many occasions 

 Avere let down even to depths of 500, 1,000, and 2,000 fathoms, and 

 thereby were discovered many swimming organisms Avhich had never 

 been captured liitherto, either at the surface of the ocean or at slight 

 depths (up to 100 fathoms l)elow the surface)" (0, ]>. 758). The most 

 characteristic forms of these zones of different depths belong chietiy to 

 the class of the Eadiolaria, especially to the order of the Fhivodaria. 



Through the investigation of the Challenger radiolaria, which occui)ied 

 for ten years the greater part of my time and attention, I was led to 

 study anew these conditions of distribution; and I reached the coii- 

 vi(;tion that the differences discovered by Murray in the pelagic fauna, 

 at different depths of the ocean, were still more significant than he 

 assumed, and that they had the greatest significance, not merely for 

 the radiolaria, but also for other groups of swimming oceanic organisms. 

 In 1881, in my '''■ Entwnrf eines Systems Her Challenger Badiolarien,''^ p. 

 422, 1 distinguished three groups: {a) pelagic, living at the surface of 

 the calm sea; (ft) zonary, living in distinct zones of dejith (to below 

 20,000 feet); and (e) profound (or abyssal) animals living immediately 

 above the bottom of the deep sea. In general, the different character- 

 istic forms coiTespond (to below 27,000 feet) to the different zones. 



In my "General Natural History of the Radiolaria^'' (4, p. 129) I have 

 established this distinction, and have expressed my conviction that it 

 is possible, by the aid of a suitable bathy graphic net, to demonstrate 

 many different fauual belts overlying one another in the great deep- 

 sea zones. 



The existence of this "intermediate pelagic fauna," discovered by 

 Murray, inhabiting the zones of different depths of the ocean between 

 the surface and tlie deep-sea bottom, which I have briefly called "zon- 

 ary fauna," has been decidedly contradicted by Alexander Agassiz. 

 He claimed, on the ground of "exact experiments" carried on during 

 the Blake expedition, in 1878, that the greater part of the ocean con- 

 tains absolutely no organic life, and that the pelngic animals go down 

 no deeper tlian 100 fathoms. "The experiments finally show that 

 the surface fauna of the sea is actually limited to a relatively thin layer, 

 and that no intermediate zone of animal life, so to speak, exists between 

 the fauna of the sea bottom ami of the surface" (15, pp. 40, 48). 



