26 BULLETIN OF THE 
But until our reports give us the exact depth of the bottom, together 
with the results of the tow-nets from the ‘so called intermediate deep-sea 
pelagic life, there is nothing to show that the contents of the nets may 
not have come from a belt of water close to the bottom, about which 
there has as yet been no discussion. 
The occurrence of animal life within a moderate distance of the bottom 
is a question which is not to be confounded with that of the lower limit 
in depth of the pelagic fauna. These two zones may meet at depths of 
500 to 700 fathoms, under favorable conditions of distance from shore, 
and give the impression of a continuous fauna from the surface to the 
very bottom. Undoubtedly a great deal of the confusion which has 
arisen regarding the lower limits of the pelagic fauna is due to differ- 
ences in our understanding of what we call deep water. To a deep-sea 
dredger the limits of the bulk of the pelagic fauna, whether it turn out 
to be 200, or 250, or even 300 fathoms, is naturally shallow water. To 
one who has been accustomed to tow merely on the surface, 50 to 100 
fathoms are already deep water, and depths below that seem enormous. 
This last expedition of Chun — which made one oceanic cast !— marks, 
so Haeckel states, the greatest progress in marine biology since the 
“Challenger ” expedition.t Yet he discards the results obtained from 
the oceanic hauls of the “ Blake,” which are the only accurate ones made 
up to the time when Hensen entered the field. He also considers Hen- 
sen’s work worthless, probably because for over three months he explored 
the surface of the Northern Atlantic as it had not been done before. 
Unfortunately, Hensen’s results do not chime with Haeckel’s precon- 
ceived ideas, and they are naturally condemned because they do not 
show below 200 fathoms the existence of a populous pelagic fauna, 
which Haeckel had decided ought to exist down to great depths, and 
which he assumes the catches made by the defective net in use in the 
“‘Vettor Pisani” and those of the open nets of the “ Challenger” to have 
conclusively proved. ‘Taking all these positive results, as Haeckel is 
pleased to call them, and adding to them the equally fictitious state- 
ments regarding the presence of an intermediate pelagic fauna, based 
upon the fact that the so called deep-sea Siphonophores were found on 
the sounding wire and dredging rope of various expeditions, he gets 
a formidable array of incomplete data, brought together by defective 
methods. Upon these grounds he bases results for which more recent 
investigations, carried on with improved machinery, furnish as yet no 
1 Ineed not say that Chun makes no such ridiculous claim for his few experi- 
ments as are put forth by Haeckel. 
