[142] Trinchese, Struttura del sistema nervoso dei Cefalopodi, Florence, 1868, p. 7.
[143] An eminent friend of mine was one day insisting to me that the physiological postulate made it impossible for a nerve-cell to be without its ingoing and outgoing fibres; and he was not a little astounded when I replied, “Come into my workroom and I will show you a thousand.”
[144] Eichhorst in Virchow’s Archiv, 1875, LXIV. p. 432.
[145] Auerbach (Ueber einen Plexus Myentericus, 1862) describes the ganglia as filled with apolar cells, among which only a few are unipolar. Stieda (Centralnervensystem der Vögel, 1868) finds both apolar and unipolar cells in the spinal ganglia of birds. Axmann (De Gangliorum Systematis Structura penitiori, 1847) says the spinal cells are all unipolar. Schwalbe (Archiv für mikros. Anat., 1868) and Courvoisier (ibid., 1869) say the same. So also Ranvier, Comptes Rendus, 1875. Kölliker (Gewebelehre) speaks decidedly in favor of both apolar and unipolar cells, but thinks the apolar are embryonic. Pagliani (Saggio sullo Stato attuale delle Cognizioni della Fisiologia intorno al Sistema nervoso, 1873), who represents the views of Moleschott, admits the existence of apolar and unipolar cells. The authors just cited are those I happen to have before me during the rewriting of this chapter, and the list might easily be extended if needful. Auerbach, Bidder, and Schweigger-Seidel describe unipolar cells which in some places present the aspect of bipolar cells simply because two cells lie together, their single poles having opposite directions. I will add that the bipolar cells do not really render the physiological interpretation a whit more easy than the unipolar, for they are simply cells which form enlargements in the course of the nerve-fibres.
[146] When Dr. Beale says “that it is probable no nerve-cell exists which has only one single fibre connected with it” (Bioplasm, p. 186), he has no doubt this in his mind; since he would not, I presume, deny that there are cells each with a single process.
[147] Deiters, Untersuchungen über Gehirn und Rückenmark, 1865.
[148] Archiv für mikros. Anat., 1869, p. 217. Compere also Butzke, Archiv für Psychiatrie, 1872, p. 584.
[149] Henle, Nervenlehre, 1871, p. 58, Fig. 21.
[150] When men of such experience and skill as Kölliker, Bidder, Goll, and Lockhart Clarke declare that they have never seen a cell-process pass directly into a dark-bordered fibre in the anterior root, what are we to say to such figures and descriptions as those given in the works of Schröder van der Kolk, Gratiolet, and Luys? Even did such arrangements exist, no transverse nor longitudinal section could display them, owing to the different planes at which the fibres enter, and the length and irregularity of their course.
[151] Long after the text was written, Willigk published in Virchow’s Archiv, 1875, LXIV. p. 163, observations of anastomoses which even Kölliker admitted to be undeniable. Yet out of sixty-four preparations, amid hundreds of cells, he could only reckon seven cases of conjunction.