. Anatomischer Anzeiger. Anatomy, Comparative; Anatomy, Comparative. 57. like the central canal, with ciliated epithelium. This secondary canal rapidly becomes larger, and shifts its position so that it lies well down in the left lateral tract, midway between the margin of the cord and the central canal. In the same section, two smaller secondary canals appear, one lying in the roof- plate almost in the mid-line. The central canal is here much narrower dorso-ventrally than in a normal [cord, and is pushed over to the right. In a few fc).;V^:¥m W0-0M c Fig. 1. Cross section of nearly nor- mal s
. Anatomischer Anzeiger. Anatomy, Comparative; Anatomy, Comparative. 57. like the central canal, with ciliated epithelium. This secondary canal rapidly becomes larger, and shifts its position so that it lies well down in the left lateral tract, midway between the margin of the cord and the central canal. In the same section, two smaller secondary canals appear, one lying in the roof- plate almost in the mid-line. The central canal is here much narrower dorso-ventrally than in a normal [cord, and is pushed over to the right. In a few fc).;V^:¥m W0-0M c Fig. 1. Cross section of nearly nor- mal spinal cord before the appearance of secondary canals, c, c. central canal. All outlines were drawn with the camera, and with the same magnification (about 80 diam.). more sections the large canal trails off, leaving no trace behind, and the small one disappears at almost exactly the same level. When it has disappeared, a new one begins. The next section shows four dark circular patches, and three of these soon show an elliptical lumen. They are very short, disappearing in a few sections, and must be nearly spherical. The central canal is rapidly growing shorter, being cut off from the dorsal side, and has acquired an elliptical outline. For a few sections the cord is without secondary canals, and then a new one appears in the position of the first, and like the first changes its position and lies in the left lateral tract. It is the largest and most persistent of the secondary canals, almost equalling in size the central canal. After this canal has dis- appeared, a small one appears on the dorsal mid- line, and at the same time another small one is found in the dorsal horn of the right side, which swells a Fig. 2. C. S. Cord with two secondary canals; the one on the right approaches more nearly to the central canal than any other secondary canal in the cord. Central canal small, c. c. central canal. S. C. secondary canal. Letters have the same reference in all the Pl
Size: 1563px × 1598px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1890, bookpublisherjenagfischer, books
