An American text-book of surgery : for practitioners and students / By Phineas S. Conner, M.D., Frederic S. Dennis, M.D., William W. Keen, M.D., Charles B. Nancrede, M.D., Roswell Park, M.D., Lewis S. Pilcher, M.D., Nicholas Senn, M.D., Francis J. Shepherd, M.D., Lewis A. Stimson, M.D., J. Collins Warren, M.D., and J. William White, M.D. Ed. by William W. Keen and J. William White.
- William Williams Keen
- Date:
- 1899
Licence: Public Domain Mark
Credit: An American text-book of surgery : for practitioners and students / By Phineas S. Conner, M.D., Frederic S. Dennis, M.D., William W. Keen, M.D., Charles B. Nancrede, M.D., Roswell Park, M.D., Lewis S. Pilcher, M.D., Nicholas Senn, M.D., Francis J. Shepherd, M.D., Lewis A. Stimson, M.D., J. Collins Warren, M.D., and J. William White, M.D. Ed. by William W. Keen and J. William White. Source: Wellcome Collection.
Provider: This material has been provided by the Augustus C. Long Health Sciences Library at Columbia University and Columbia University Libraries/Information Services, through the Medical Heritage Library. The original may be consulted at the the Augustus C. Long Health Sciences Library at Columbia University and Columbia University.
![a mode of cell-division is iil)oiit tf) take ])lacc, the delicate reticulum of fiber of which the nucleus is composed when in the (juiescent state—an<l which is called chromatine substance, from its capacity to take staining fluids—becomes con- Fk;. 11. Karyokinesis, or Iiulirect Cell-division (Zieglon: «, cell with nucleus in iiwiescent state. The nucleus contains nucleoli and a network of threads ; h, formation of coarse chromatine threads in nucleus ; f, disappearance of nucleolus and membrane of nucleus; arrangement of threads in loops forming the rosette ; </, angles of loops directed toward the poles of the cell, which are formed of achro- matic threads; c, beginning division of the cell; this is followed by a gradual return of the nucleus to the quiescent state (a). verted into a skein of contorted filaments, wliicli rrradually assumes the shape of a rosette, and subsequently a star. Mean-vvhile the wall of the nucleus has dis- appeared. In a later or equatorial starje of the process the star-shaped mass of filaments separate into two groups, which dispose themselves around the two poles of the nucleus, leaving a clear space in the plane of the equator. When the nucleus has thus divided the filaments return to their former quiescent state. The protoplasm is contracted along the line of equatorial division, and the division of the cells becomes complete (Quain). The new cells, or fihrohlasis, as they are called, become elongated by the formation of prolongations from their extremi- ties, and, as shown above, develop fibrillse by a differentiation of their proto- phism. Examples of ivoimds of hJoodlcKn tissues are seen in the cornea and in car- tilage. When the cornea is divided and the wound gapes, it is filled in at first partly by a coagulum of fibrin, and partly by a growth of e])ithelial cells. At the end of a few days the corneal corpuscles begin to proliferate and push aside the elements which occupy the cleft, and thus permanently close the wound. In cartilage, owing to the poor supply of nutriment, the cells appear to take but a feeble ])art in the process of repair. Incised wounds of joint-cartilage are found many weeks after the injury filled with a clot of fibrin, which eventually is replaced by connective tissue. The cartilage-cells near the wound become polynucleated, and the intercellular substance becomes fibrillated, but this is probably only a retrograde metamorphosis. Neiv epidermis is formed by proliferation of the epithelial cells. New epithelial cells possess amoeboid movements, and may wander a short distance from ilie margin of the wound. The deep layers of the rete mucosum furnish cells which multiply rapidly, and it is this layer of the skin which is utilized by Reverdin in transplanting small grafts to the granulations. The success of the Thiersch method, which consists in the transplantation of portions of skin several inches in length to the freshly-cut surface of open wounds, is due to this fact. The grafts are cut with the razor and are exceedingly thin, so that only the most superficial portions of the skin are removed. Refjeneration of striped muscular liher occurs to some extent in slight injuries. The cicatrix following a wound in the muscle is, however, usually composed of connective tissue, and the fragments of the muscle are thus united by a tendin- ous mass. At first an increase in the size and number of the muscular nuclei](https://iiif.wellcomecollection.org/image/b21217014_0064.jp2/full/800%2C/0/default.jpg)
