202 THREE CRUISES OF THE “ BLAKE." 
On the 15th of July, in Lat. 34° 28’ 25" N., Lon. 75° 99' 50" 
W., we tried the Sigsbee cylinder for a third time, in a depth 
of 1,632 fathoms. With the same precautions before and 
after using it, the cylinder was operated first between five and 
fifty fathoms (time 30”). Тһе water was somewhat ruffled, and 
but little was found on the surface beyond a few crustacean 
larvee and heteropods. The cylinder contained hydroids, frag- 
ments of siphonophores, pelagic algw, crustacean larvee, and het- 
eropod eggs; forms which differed from those gathered at the 
surface, but were identical with the species obtained on previous 
days under more favorable conditions of the sea. Next, the cyl- 
inder was arranged for a depth of between fifty and a hundred 
fathoms (time of messenger 21” from surface to fifty fathoms, 
time of cylinder 40" to stopper from fifty to a hundred fath- 
oms) The water was found to contain only a couple of 
Squill larvae, similar to those fished up at the surface. The 
third time the cylinder went down at this station, it was lowered 
to collect from a hundred to a hundred and fifty fathoms (time 
of messenger from surface to a hundred fathoms 45”, time of 
cylinder in passing from a hundred to a hundred and fifty fath- 
oms 45"). The water when examined contained nothing. No 
radiolarians were found at this station, either at the surface or 
at any depth to which the cylinder was lowered (one hundred 
and fifty fathoms). 
The above experiments appear to prove conclusively that the 
surface fauna of the sea is really limited to a comparatively 
narrow belt in depth, and that there is no intermediate belt, 
so to speak, of animal life, between those living on the bot 
tom, or close to it, and the surface pelagic fauna. It seems 
natural to suppose that this surface fauna only sinks out of 
reach of the disturbances of the top, and does not extend 
downward to any depth. The dependence of all the pelagic 
forms upon food which is most abundant at the surface, or near 
it, would naturally keep them where they found it in quantity. 
The experiments in using the tow-net at depths of five hun- 
dred to one thousand fathoms, as was done by Mr. Murray 
on the “ Challenger," were not conclusive, as has been already 
pointed out on a former occasion, while the so-called deep-sea 
