THE RADIATING ORGANS OF THE DEEP SEA FISHES. 205 
3. CONCLUSIONS. 
The results of the examination of the minute structure of the organs 
of the fishes collected by the “ Albatross” which one can, with more or less 
certainty, consider as radiating, as described above, illustrate again their 
great diversity. Not only do the ocellar, dise-shaped, and tubular organs 
fundamentally differ, but even within these three main groups very great 
variations are met, with. 
The best known of those organs are the ocellar. A highly developed 
apart 
organ of this kind, such as the compound organ of Chauliodus is 
from the connective-tissue support, the nerves and blood vessels — composed 
of a pigment sheath, a reflecting layer, an inner region of large, highly 
specialized conic cells, and a middle and an outer mass of specialized 
polyedrical cells of another kind. Apart from the blood vessels, nerves, 
in all organs, of course do not 
are found in adi of the ocellar 
and connective tissue, which, as occurring 
concern us here, none of these structures 
organs described above as radiating. The pigment sheath is absent in the 
smallest organs of Chauliodus itself. In these, and in others with a pigment 
sheath, the reflecting layer is absent. The large conic cells of the inner 
region are absent in the simple organs and in the highly differentiated 
compound organs of Argyropelecus. The polyedrical cells of the middle 
and outer region of the compound organs of Chauliodus which usually 
occur in simple organs are replaced by long spindle-shaped cells in all the 
compound organs of Lychnopoles and in the anterior compound organs 
of Stomias. 
An analogous diversity is met with in the radiating dises. Whilst in 
Halosaurus and Ipnops_ highly specialized cylindrical or spindle-shaped 
elements, obviously forming a very essential part of the organ, are met 
with, such cells seem to be entirely absent in the dises of Bassozetus and 
Leucicorus. 
In the tubular organs the diversity is not so great, although here also 
we find the cells forming the walls of the glandular tubes sometimes high, 
as in Malthopsis, and sometimes low, as in Pachystomias. 
Even the rule, in general holding good, that the outer covering of these 
organs is transparent and suited to allow the radiation to pass, is not univer- 
