THE RADIATING ORGANS OF THE DEEP SEA FISHES. 189 
proximal mass which Leuckart terms “ Glaskirper,” and which corresponds 
to the inner region, is composed of large crystal-clear radial cones similar to 
cells; Leuckart, however, does not consider them as such, not having been 
able to find a nucleus in them. Each organ is supplied by a slender nerve. 
Leuckart considers these organs as accessory eyes, “ Nebenaugen.” It is 
noteworthy that in the discussion following the reading of this paper Claus 
(Leuckart, ’64, p. 155) drew attention to the similarity between these organs 
and the well-known structures of EKuphausia, which were at that time also 
considered as accessory eyes. 
Ussow (’79, pp. 94-97, Plate 1, Figs. 1, 2, Plate 4, Figs. 25, 26) has also 
described the structure of the compound radiating organs of ©. sloani. He 
finds them composed of two semispherical parts, the outer one of which is 
occupied by a gelatinous mass, colorless and transparent in the living fish, 
but coagulating and becoming opaque on being treated with the reagents 
used for preserving the specimen. Below this gelatinous mass a mushroom- 
shaped “lens” (79, Plate 2, Fig. 6 Kl) is seen, the cylindrical stalk 
of which extends inwards, whilst the semispherical upper part, com- 
posed of conic elements, protrudes into the outer gelatinous mass. This 
“Tens” appears to correspond to our middle region. The conic elements 
of its distal, semispherical part are according to Ussow attenuated proxi- 
mally to fine threads, which extend inward parallel to the axis of the organ 
and form the stalk of the mushroom, in which they are connected with 
granular multipolar cells, Concerning the inner region Ussow merely 
corroborates the previous statements of Leuckart. These, however, he does 
not seem correctly to have understood. Ussow also states that a slender 
nerve leads to each organ. His description and also his figures are very 
different from what subsequent authors have seen in these organs of C. 
sloani and show very little similarity to the structure of these organs in 
C. barbatus described above. 
Leydig (79, pp. 8365-382, Plate 15) examined the radiating organs of (. 
sloam simultaneously with and independently of Ussow. His material, a 
specimen preserved in spirits for several years, was not good, but nevertheless 
his results were more valuable than those of Leuckart and Ussow. He algo 
chiefly studied the compound organs; his notes on the others have been 
referred to above. The compound organs are surrounded by annular blood 
vessels and a slender nerve branch leads to each. The distal portion of the 
compound organ is composed of two parts, an outer cap and a lower mass. 
