THE PELAGIC FAUNA AND FLORA. 203 
siphonophores, taken from the sounding-line by Dr. Studer on 
the “ Gazelle,” may have come, as I have so often observed in 
the Caribbean, from any depth. I do not mean, of course, to 
deny that there are deep-sea meduse. The habit common to 
so many of our acalephs (Tima, /Equorea, Ptychogena, ete.) of 
swimming near the bottom is well known ; Dactylometra moves 
near the bottom, and Polyclonia remains during the day turned 
up with the disc downwards on the mud bottom. I only wish 
to call attention to the uncertain methods adopted for deter- 
mining at what depth they actually live. 
One must have sailed through miles of Заір, with the asso- 
ciated crustacean, annelid, and mollusk larvee, the acalephs, 
especially the oceanic siphonophores, the pteropods and heter- 
opods, with the radiolarians, globigerin, and algæ, to form an 
idea of how rich a field still remains to be explored. The 
pelagic fauna in the course of the Gulf Stream is probably not 
surpassed in variety by that of any other part of the ocean. 
When they die and decompose, the pelagic forms, both ani- 
mal and vegetable, sink to the bottom fast enough to form an 
important part of the food supply of the deep-se: animals, as 
can easily be ascertained by examining the intestines of the 
deep-water echinoderms. We can thus account for the pre- 
sence at great depths of much of the necessary plant-food 
needed for the herbivorous types living in the continental and 
abyssal regions. The variety and abundance of the pelagic 
fauna and "Вота, and their importance as food for marine ani- 
mals, are as yet hardly realized. 
According to the recent investigations of Regnard and Certes, 
decay and decomposition do not progress rapidly in deep water, 
the great pressure and the absence of light and heat being un- 
favorable to such progress. This mass of slowly decomposing 
material, which accumulates on the bottom of the ocean, mixing 
with the ooze, forms the organic slime which all dredgers have 
brought up, and which in ently days of deep-sea investigations 
was regarded as a special organism of the highest scientific 
interest. 
There seemed something providential, indeed, in the existence 
of this primordial pap, laid out in the thinnest layers over the 
