254 THE RETINA, BY MAX SCHULTZE. 



extremely fine longitudinal lines running either in a straight 

 direction, or in easy spirals, upon the highly refractile external 

 segments of the rods of Man. * 



As has already been stated, these fibres are capable of being 

 partially isolated. At the base of the cones in particular they 

 are easily separable for a certain constant length, and remain, 

 forming by their continuity a short tube composed of stiff 

 fibrils, seated on the membrana lirnitans externa, where the 

 cones have themselves become detached from this membrane. f 

 Examined from the surface, the limitans externa then appears 

 to be finely punctated in circles, the diameter of which corre- 

 sponds with that of the cones, J and gives the impression that 

 the fibrils, of which we considered the cone fibres in the outer 

 granule layer to be composed, here run separately upon the 

 surface of the bodies of the cones. In this event the fibrils 

 would be nerves. Nevertheless, this does not appear to be 

 the case. The fine fibrils can only be followed backwards into 

 the outer granule layer with very great difficulty. I have, 

 however, ascertained this much with certainty, that they are 

 continuous with the tissue intervening between the rod and 

 cone fibres. As this can only be considered to be connective 

 tissue, the fibres in question must represent a prolongation of 

 the delicate and already finely fibrillated or striated connective 

 tissue of the outer granule layer, and form to this extent 

 isolable " supporting basketworks" or cradles for the bases of 

 the cones and rods, (see below, fig. 360). The further superficial 

 relations of these fibres, especially in the case of the cones of 

 Man, are rendered doubtful by a fresh complication of structure 



* Max Schultze, loc. cit., Taf. xxii., figs. 7 16. 



-f I have depicted very incomplete portions of these fibres in the Ar- 

 chivfiir Mikroskop. Anatomie, Band ii., Taf. xi., fig. 13a, and they have 

 been described by W. Krause, who has applied the term "needles" to 

 them, as forming a distinct constituent of the retina. Membrana fenes- 

 trata, figs. 4, 5, 21. 



J Archivfiir Mikroskop. Anatomie, Band v., Taf. xxii., fig. 6. 



Landolt has recently described, in the Archivfiir Mikroskop. Anatomie, 

 Band vii. , p. 94, a sheath-like prolongation of the connecting substance 

 over the rods in Amphibia, which must in all essential respects agree 

 with the above-named " fibre-baskets " of the cones of Man. 



