124 PATTEN. [Vou. II. 
them as half-formed ganglion-cells which have not succeeded 
in separating themselves from among the sensory cells, by 
transformation of which they arose. 
NERVE Enps.— The manner in which the nerves terminate in 
the retina is practically the same as in eye V., while owing to 
the large size of the inner retinal cells, some points are brought 
out with great clearness. But the layer of pigmented nerve 
fibres between the rows of gigantic cells is a fedture only 
found where these cells are especially well developed. 
In Fig. 56, Pl. X., is represented a section through the hori- 
zontal furrow of eye I. The sides of the cells are thickly cov- 
ered with nerve fibres that converge toward the inner end of 
the cell to form a large bundle that might readily be mistaken 
for a continuation of the cell substance. The fibres follow, as 
nearly as possible, the contours of the outer and inner edges of 
the cell. This point is of importance, for it furnishes additional 
evidence that the rods belonging to these cells are terminal, and 
consequently developed at what is morphologically the free end 
of the cell; for in the smaller retinal cells the nerve fibres always 
run parallel with the longitudinal axis; hence the direction of 
the fibres shows in which way the cells have been bent. 
At the distal end of the cell all the nerve fibres become 
roughly parallel, and develop refractive, spindle-shaped swell- 
ings, densely coated with pigment, the granules of which often 
form distinct lines, showing clearly the position and direction of 
the nerve fibres around which they are arranged; or the gran- 
ules may be collected in shapeless masses near the inner end of 
the rod, showing no traces of the arrangement of the nerve 
fibres they so effectually conceal. 
At the opposite extremities of the cells the pigment granules 
are arranged in lines similar in direction to the nerve fibres ; 
they are also found on the nerve fibres after they have left the 
cell to form the optic nerve. 
Beyond the spindle layer described above, the nerve fibres 
emerge from the pigment and extend over the surface of the 
rods in nearly parallel lines. At certain intervals these fibres 
expand into spindles, which were a sore puzzle to me before I 
had made a careful study of depigmented sections. They 
seemed to indicate quite clearly the division of the broad rods 
into segments, about the width of the smaller rods, a condition 
