Note 171 — Chapter VII · THE ELEMENTARY STRUCTURE OF THE NERVOUS SYSTEM.
Reading edition
Monthly Journal of Micros. Science, XI. 219. This accords with what Kupffer says respecting the entire absence of cells in the earliest stages observed by him in the sheep. The white substance of the spinal cord he describes as soft, transparent, and gelatinous, in which dark points are visible; these dark points are seen in longitudinal sections to arise from the fibrillation of the substance.—Bidder und Kupffer, Op. cit., p. 111.