PLATE 1 
EXPLANATION OF FIGURES 
The drawings were made from pyridine-silver preparations of the degener- 
ating and regenerating sciatic nerve of the adult dog. 
1 Ocu. 3, Obj. 2 mm. Degenerating medullated axon in the distal stump 
on the second day. 
2 Ocu. 3, Obj. 2mm. Two medullated fibers from the distal stump on the 
fourth day. Degeneration has progressed much farther in a, than in b. The 
neurilemma can be seen bounding the unstained myelin sheath. 
3 Ocu. 3, Obj. 2mm. Medullated fiber from the distal stump on the eighth 
day; a, fragmented axon surrounded by an elliptical segment of myelin. 
4 Ocu. 3, Obj. 2mm. Early protoplasmic band formed from a medullated 
fiber. From the distal stump on the nineteenth day; a, nucleus; b, droplet of 
myelin containing fragments of axon. 
5 Ocu. 3, Obj.2mm. A bundle of degenerating non-medullated fibers from 
the distal stump on the second day. 
6 Ocu. 3, Obj. 2mm. Undegenerated non-medullated fiber from the distal 
stump on the fourteenth day. 
7 Ocu. 3, Obj. 2mm. Three protoplasmic bands formed from non-medul- 
lated fibers. From the distal stump on the nineteenth day. 
8 Ocu. 3, Obj. 2mm. Non-medullated fiber from the neighborhood of the 
cut surface of the distal stump, showing new formed lateral branch with end- 
bulb. End of first day; c, toward the center; p, toward. the periphery. 
9 Ocu. 3, Obj. 2 mm. Non-medullated fiber from the neighborhood of the 
cut surface of the distal stump, showing branching and two end-bulbs.. End 
of first day; c, toward the center; p, toward the periphery. 
10 Ocu. 3, Obj. 7. Medullated fiber from the neighborhood of the cut sur- 
face of the distal stump on the third day; a, disintegrated portion of the axon; 
b, club-shaped extremity of the living part of the axon; d, isolated neurofibril; 
c, toward the center; p, toward the periphery. 
11 Ocu. 3, Obj. 2mm. Medullated fiber from the neighborhood of the cut 
surface of the distal stump on the third day, showing fibrillar reticulum, iso- 
lated fibrils, and one fibrillar side branch with bulb; c, c’, toward the center; p, 
toward the periphery. 
12 Ocu. 3, Obj. 2 mm. Formation of side branches and end-bulbs on the 
non-medullated fibers near the cut surface of the proximal stump at the end of 
the first day. 
538 
