{"id":484,"date":"2023-11-24T02:18:33","date_gmt":"2023-11-24T02:18:33","guid":{"rendered":"https:\/\/cellandcelldivision.com\/?p=484"},"modified":"2024-01-30T23:42:28","modified_gmt":"2024-01-30T23:42:28","slug":"page-66","status":"publish","type":"post","link":"https:\/\/cellandcelldivision.com\/?p=484","title":{"rendered":"Page 66"},"content":{"rendered":"\n

grains are formed, which by way of condensation form a nucleolus and a
proper nucleus after that. On the surface of the nucleus again from mucous
substances a membrane is formed, which confines the space holding the
nucleus. This space according to Schleiden is the newly formed cell.
Similar is the theory of cytoplasts by Schwann. The difference between
them is that according to Schleiden the cell-forming substances are found
inside the cell, while Schwann admits that they can also be found in the
intracellular spaces.
A common weakness of both theories is the assumption of a possibility
for spontaneous cell formation through crystallization of mucous
substances. This understanding was opposed by F. Unger (1841\u201455), K.
N\u00e4geli (1842\u201446), H. von Mohl (1835\u201451), etc. Their studies gradually
have been leading to the viewpoint that the formation of new cells is via cell
division. Attribute in this trend is also the premise of R. Virchow (1855,
1858) \u2014 \u201cOmnis cellula e cellula\u201d. This formulation of his was accepted as
a law of biology by some authors since modern science does not know any
other way for cell reproduction except through division.
With the discovery of cell division (see Chapter 3, Section 3.2), and the
refuting of the incorrect concepts about the cell formation, the studies have
taken along the right path. The attention of the investigators was drawn to
the content surrounded by cell walls. It was already regarded as live
matter<\/strong> which was called sarcoda<\/strong> by F. Dujardin in 1835. The term
protoplasm<\/strong> was introduced by J. Purkinje (1839) in the animal cells and by
H. von Mohl (1846) for the plant cells. Several years after that F. Cohn
(1850) has arrived at the conclusion \u201cthat optical, chemical and physical
properties of these two substances are similar\u201d.
The studies in this period were intense and versatile. They have
served for the rise of various viewpoints, hypotheses and theories which
have finally led to the summarized idea that morphologically the cells
consist of cell membrane, cytoplasm and nucleus. Ernst Br\u00fccke (1862)
has for the first time looked upon the cell as an elementary organism,<\/strong>
which has marked a new stage in the process of its study.
This concept about the structural organization of the cell has
strongly stimulated the studies on the processes and phenomena taking
place in the cytoplasm. Different pictures about this structure were
forwarded \u2014 fibrous, granular, reticular, etc. Some of its organelles have
also been discovered \u2014 the cell centre by E. van Beneden,
chondriosomes (mitochondria) by C. Benda, the Golgi apparatus, etc.
which will be described later (Section 2.8).
In the second half of the XIX century the studies on the cell have given
rise to an individual science \u2014 Cytology <\/strong>(Greek: k\u00fdtos \u2014 cell and logos \u2014
science). The beginning was marked by the two capital books \u2014 \u201cBiology
of the Cell\u201d by J. Carnoy (1884) and \u201cCell and Tissue\u201d by O. Hertwig
(1893\u201498).<\/p>\n","protected":false},"excerpt":{"rendered":"

grains are formed, which by way of condensation form a nucleolus and aproper nucleus after that. On the surface of the nucleus again from mucoussubstances a membrane is formed, which confines the space holding thenucleus. This space according to Schleiden is the newly formed cell.Similar is the theory of cytoplasts by Schwann. The difference betweenthem […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"set","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"categories":[6],"tags":[],"class_list":["post-484","post","type-post","status-publish","format-standard","hentry","category-book"],"_links":{"self":[{"href":"https:\/\/cellandcelldivision.com\/index.php?rest_route=\/wp\/v2\/posts\/484","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/cellandcelldivision.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/cellandcelldivision.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/cellandcelldivision.com\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/cellandcelldivision.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=484"}],"version-history":[{"count":1,"href":"https:\/\/cellandcelldivision.com\/index.php?rest_route=\/wp\/v2\/posts\/484\/revisions"}],"predecessor-version":[{"id":490,"href":"https:\/\/cellandcelldivision.com\/index.php?rest_route=\/wp\/v2\/posts\/484\/revisions\/490"}],"wp:attachment":[{"href":"https:\/\/cellandcelldivision.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=484"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cellandcelldivision.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=484"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cellandcelldivision.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=484"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}