Cited by W.H. Howell and G.C. Huber, 'A Physiological, Histological and Clinical Study of the Degeneration and Regeneration in Peripheral Nerve Fibres', Journal of Physiology 13 (5) (1892), pp. 335-406
Tags: haemotoxylin, osmic acid, picric acid, gold
Description:

Explanation of Plate XVII (figs. 70-76):

'Figs. 70, 71, 72. To show the connection between the axis cylinder of the old and the new fibre. Compare 71 with figs. 64, 65. Exp. XXII. Central ulnar after 75 days, no union. Picric acid and haematoxylin.

Fig. 73. To show the formation of two embryonic fibres in a fibre of central end near the wound, connecting a distal piece which has not degenerated. Central end of human ulnar 61 months after injury. Gold and haematoxylin.

Fig. 74. To show intercalated pieces of newly formed fibres without degeneration of distal end. Exp. XVII. L. S. 4 weeks. Wound. Osmic acid and haematoxylin.

Fig. 75. The same, from central end of ulnar (Exp. XXII.) 75 days after section, shows the axis cylinder in the intercalated piece and its connection on each side with the intact axis of old fibre. Picric acid and haematoxylin.

Fig. 76. The same. Exp. XXII. Central end of ulnar after 75 days. Picric acid and haematoxylin.' (406)

 

Figs. 70-72 in text:

'We have not followed all the stages of degeneration and regeneration in the central end with the same care as in the peripheral end; but the stages we have examined have convinced us that the processes are practically identical in the two ends. The myeline and axis disintegrate and are absorbed for a certain distance; an embryonic fibre is formed from the new protoplasm arising from the nuclei, and in this a myeline sheath is first formed into which an axis cylinder penetrates as an outgrowth from the end of the old axis. Various examnples of this formation of a new fibre within the sheath of the old are shown in Figs. 62 to 72. In many cases, in the central end, when union was not made or when difficult union was made as in cross sutures, an old fibre was found to terminate in a bunch of two or more new fibres (see Figs. 62 and 63), usually coiled round one another so that they could not be disentangled.' (382)

'Similar preparations were obtained from the central end of the ulnar, in a dog, which had been severed 75 days before the examination was made, and had not been allowed to unite with the peripheral end. In some of the specimens from this latter nerve the mode of union of the axis cylinder in the newly regenerated fibre with the axis in the old fibre is clearly shown (Figs. 70, 71, and 72). Fig. 71 is particularly instructive when compared with Figs. 64 and 65. The new axis cylinder is seen to escape the swollen end of the old fibre and to penetrate the inyeline some distance beyond this point in order to reach the old axis. Fig. 72 shows the end of an old axis cylinder enlarged and sending out a new axis.' (383-384)

 

Figs. 73-76 in text:

'In conclusion we wish to speak briefly of an appearance often seen in the central end of the nerve, whether or not union is made with the peripheral end, an appearance which has been frequently described by other observers, but which has not been explained, as far as we are aware. This phenomenon consists in the intercalation of a segment of one or even two new fibres between the ends of an old fibre which has not undergone degeneration. (See Figs. 73, 74, 75, 76.) The noteworthy thing is the apparent exception to the general rule that the distal portion of a severed fibre always degenerates.' (384)