3 o8 



A. TKKAO : 



at the inner end and more or less narrowed towards the outer end, with 

 which they stand in contact with the lens epithelium. Some seven or so of 

 them in a row may be seen in a section passing through the axis of the 

 photophore. While the central photogenous cell or cells stand with their 

 long axes vertically disposed to the internal lens surface, the more 

 peripherally situated ones are all obliquely set, with their outer ends so 

 inclined that outward prolongations of their long axes converge toward a 

 point well within, and approximately in the axis of, the photophore. It will 

 be noticed that this arrangement of the photogenous cells agrees with that 

 of the projecting nuclei of the lens epithelium, — a fact, which may be taken 

 as suggestive of the derivation of the former from the cell-bodies of the 

 latter. 



The photogenous cells do not form a compact layer. There exist 

 between them interstices of a considerable width. These intercellular 

 spaces are clearly not artefacts, but are evidently haemal spaces, as was 

 stated by Chun 1 ' for the photophores of EupJiausia. They are occupied by 

 a clear substance which is stained bluish by Freeborn's picro-nigrosin, 

 exactly like the blood. Further, the spaces, as seen in sections, are frequent- 

 ly, but not always, traversed by fine strands {cs), the connective strands 

 (" Bindesubstanz " of Grobbeir'), which extend between the lens epithelium 

 and the basement membrane of the photogenous layer. The strands are 

 evidently protoplasmic and are directly continuous with the substance of 

 the basement membrane. A nucleus was never observed to be present in 

 the strands. 



The nucleus of the photogenous cell is found about midway between 

 the ends of the cell-body, always more or less closely pressed against the 

 lateral cell-wall. It is relatively very small, elongate in shape (about S u 

 long) and of a rather compact appearance. On account of its insignificant 

 size, disproportionate to the bulky development of the cell-body, it may 



1) Chun, C, 1893. Sehorgane und Facettenauge. Ein Beitrag zur Theorie des Sehens in 

 grossen Meerestiefen. Biol. Centrait)., Bd. 13, p. 550. 



2) Grobben, K., ign. Die Bindesubstanzen von Argidus. Ein Beitrag zur Kenntnis der 

 Bindesubstanz der Arthropoden. Arb. Zool. Inst. Wien, Bd. 19. 



