Principles of surgery / By N. Senn ... Illustrated with 109 wood-engravings.
- Nicholas Senn
- Date:
- 1890
Licence: Public Domain Mark
Credit: Principles of surgery / By N. Senn ... Illustrated with 109 wood-engravings. 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.
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![the formation of new tissue; hence, in this connection should be given a description of KARYOKINESIS. Karyolvinesis, or karyomitosis, as described by Flemming, is the in- direct reproduction of cells as compared with direct cell-division by segmentation. It is a process by which the net-work of chromatin tlireads within the nucleus undergoes great development, and is snbject to certain transformations of form, which are instrumental in ertecting division of nucleus and cell. The term karyokinesi.s was first used by Schleicher, and the first accurate description of the process, as seen in the cells of a number of animals, simple in form and structure, was given by Biitschli in 18Y6. The motlern definition of a cell is much more com- plicated than that given b}^ Schleiden and Schwann, as recent researches have shown that it is not such a simple structure as it was formerly Fig. .3.—Quiescent Nucleus. Epithelial Cell of Salamander Entering upon THE Glomerular Phase. {Flem- ming. ) Fig. 4.—Living Cell of Salamander. (Flemniinff.) A, granules aggreg.^ted round a pole of the cell; B, coils of glomerular net-work; C, cell-body. believed to be. When we speak of a cell now we mean a mass of cir- cumscribed living substance, with or without an envelope, which con- tains as an essential element in its interior a nucleus, with the property of forming new compounds out of substances taken into it, and is capable of reproduction by division. Both the nucleus and cell are composed of threads and intermediate substance. The cell-body consists of threads somewhat irregularly distributed, seldom forming a net-work, embedded in a homogeneous substance. The nuclear threads stain with liaima- toxylon and safranin, and hence are called chromatin threads, Aviiich are arranged in a net-like figure, the meshes of which are filled with a sub- stance which cannot be stained, and hence is named by Flemming achromatwe. The nucleus is surrounded bj^ a membrane composed of two la3'ers; the inner can be stained, but not the outer. The nucleoli, usually multi])le, are made up of a substance more refractile than the structures described in the nucleus. They are round and smooth, and](https://iiif.wellcomecollection.org/image/b21207501_0028.jp2/full/800%2C/0/default.jpg)
