DR. MARTIN BARRY ON FIBRE. 95 



the remarkable arrangement of the two lines of rings at a. For, during the transi- 

 tion (as 1 suppose) of the rings into coils, an interlacement is almost a necessary con- 

 sequence of the alternate succession of the rings. I have also seen this interlacement 

 of spirals provided for, apparently, by the rings of several lines being linked together 

 while still rings (fig. 47 : see also fig. 120). 



24. Figure 48, from its exhibiting only one side of the tube, represents but two rows 

 of rings. The number of rows, however, contained in the tube seemed four: which 

 of course would become connected in the above way, as easily as two ; and give 

 origin to a corresponding number of interlacing spirals. 



25. I cannot suppose that minuteness is any hindrance to the smallest filament 

 (" fibre") having its origin by the same mode : and to this, the linear arrangement of 

 the discs irit/i/n the blood-corpuscle seems to have especial reference-^-. Facts will be 

 hereafter mentioned, which seem to show a fasciculus of filaments to be thus produced 

 in a certain tissue (par. 42 44). 



26. Within the windings of the spirals (fig. 57 ), nuclei are 'sometimes to be dis- 

 cerned. It appears to be from these nuclei that there proceeds the substance for 

 forming new filaments (fig. 22); which are very often seen within the winds of spirals 

 (figs. 131 (3,94, 58). 



27. I have in some instances observed the filaments, when enlarging, to present a 

 remarkable change in the relative position of their spiral threads. If figs. 40, 41 be 

 referred to, it wiil be seen that a of fig. 40 passes into u of fig. 41, and the latter into 

 )8 of the same figure. The scheme fig. 60 may illustrate this transition. This scheme 

 is merely an altered state of that in fig. 55. In each there are two spirals ; the dif- 

 ference consisting in the relative position of the spirals. The points in contact at a 

 fig. 55, have separated in fig. 60 (a, a) ; so that now, a transverse section is no longer 

 represented by the figure 8 (par. 14), but by a circle. This latter (fig. 60) seems 

 to exhibit the relative position of the spirals, in some instances, when they begin to 

 form, as will be hereafter shown, the membrane of a tube. Such appears to be their 

 state in fig. 41. |3 : a state which apparently precedes the formation of the tubes in 

 figs. 42, 43, and the subsequent figures in this Plate. 



Facts observed in the Formation and Structure of Nerve. 



28. It is known that in the so-called " primitive fibres" into which a nerve can be 

 separated by means of needles, REMAK demonstrated a " band-like axis:}:," corre- 

 sponding to the "cylindrical axis of PURKINJE^;" and that the substance surround- 

 ing this axis, has been termed by SCHWANN, the " white substance of the nervous 

 fibre J." This "white substance" I find to consist of filaments (fig. 112 a, ft fig. 



t See my Part III. on the Corpuscles of the Blood, Philosophical Transactions, 1841, Plate XVIII. 

 figs. 52 y, 54 f. 



t MULLEK'S Elements of Physiology, translated by Dr. BALY, Part VI. p. 1649. 



