Jump to content
Main menu
Main menu
move to sidebar
hide
Navigation
Main page
Recent changes
Random page
Help about MediaWiki
Special pages
Niidae Wiki
Search
Search
Appearance
Create account
Log in
Personal tools
Create account
Log in
Pages for logged out editors
learn more
Contributions
Talk
Editing
Karl Ernst von Baer
(section)
Page
Discussion
English
Read
Edit
View history
Tools
Tools
move to sidebar
hide
Actions
Read
Edit
View history
General
What links here
Related changes
Page information
Appearance
move to sidebar
hide
Warning:
You are not logged in. Your IP address will be publicly visible if you make any edits. If you
log in
or
create an account
, your edits will be attributed to your username, along with other benefits.
Anti-spam check. Do
not
fill this in!
===Embryology=== {{See also|Recapitulation theory}} Von Baer studied the embryonic development of animals, discovering the [[blastula]] stage of development and the [[notochord]]. Together with [[Heinz Christian Pander]] and based on the work by [[Caspar Friedrich Wolff]], he described the [[germ layer]] theory of development ([[ectoderm]], [[mesoderm]], and [[endoderm]]) as a principle in a variety of species, laying the foundation for [[comparative embryology]] in the book ''Γber Entwickelungsgeschichte der Thiere'' (1828). In 1826, Baer discovered the mammalian [[ovum]]. The human ovum was first described by [[Edgar Allen]] in 1928. In 1827, he completed research ''Ovi Mammalium et Hominis genesi'' for St Petersburg's Academy of Science (published at Leipzig<!-- the following archived URL is not working. Checked September 2021 --><ref>{{cite web|url=http://safety.spbstu.ru/book/hrono/hrono/biograf/bio_b/ber_karl.html|title=Bibliographic Index β Baer Carl|url-status=bot: unknown|archive-url=https://web.archive.org/web/20060521214120/http://safety.spbstu.ru/book/hrono/hrono/biograf/bio_b/ber_karl.html|archive-date=21 May 2006}} via [https://translate.google.com/translate?hl=en&sl=ru&tl=en&u=https%3A%2F%2Fweb.archive.org%2Fweb%2F20060521214120%2Fhttp%3A%2F%2Fsafety.spbstu.ru%2Fbook%2Fhrono%2Fhrono%2Fbiograf%2Fbio_b%2Fber_karl.html Google Translate]</ref><ref>{{cite web|url=http://www.allpersona.ru/people/72032.html|title=Biography Karl Maximovych|url-status=bot: unknown|archive-url=https://web.archive.org/web/20080319143038/http://www.allpersona.ru/people/72032.html|archive-date=19 March 2008}} via [https://translate.google.com/translate?hl=en&sl=ru&tl=en&u=https%3A%2F%2Fweb.archive.org%2Fweb%2F20080319143038%2Fhttp%3A%2F%2Fwww.allpersona.ru%2Fpeople%2F72032.html Google Translate]</ref>). In 1827 von Baer became the first person to observe human [[Egg cell|ova]].<ref name="discover">{{cite journal |vauthors=Cobb M | title=An amazing 10 years: the discovery of egg and sperm in the 17th century | journal=Reprod Domest Anim | volume=47 | issue=Suppl 4 | year=2012 | doi = 10.1111/j.1439-0531.2012.02105.x | pmid=22827343 | pages=2β6| doi-access=free }}</ref><ref>{{cite web|url=http://commons.wikimedia.org/wiki/File:%22Conclusio%22_from_Carl_Ernst_von_Baer%27s_De_Ovi_Mammalium_et..._Wellcome_L0013369.jpg|type=jpeg|title="Conclusio" from Carl Ernst von Baer's De Ovi Mammalium et...|access-date=2 February 2015|archive-date=24 May 2019|archive-url=https://web.archive.org/web/20190524022453/https://commons.wikimedia.org/wiki/File%3A%22Conclusio%22_from_Carl_Ernst_von_Baer%27s_De_Ovi_Mammalium_et..._Wellcome_L0013369.jpg|url-status=live}}</ref> Only in 1876 did [[Oscar Hertwig]] prove that fertilization is due to fusion of an egg and sperm cell.<ref name="fertile">{{cite journal |vauthors=Clift D, Schuh M | title=Restarting life: fertilization and the transition from meiosis to mitosis (Box 1) | journal=[[Nature Reviews Molecular Cell Biology]] | volume=14 | issue=9 | year=2013 | pages=549β62 | doi = 10.1038/nrm3643 | pmc = 4021448 | pmid=23942453}}</ref> von Baer formulated what became known as [[Von Baer's law (biology)|Baer's laws of embryology]]: # '''General characteristics''' of the group to which an embryo belongs develop '''before special''' characteristics. # '''General structural relations''' are likewise formed '''before''' the most '''specific''' appear. # The form of any given embryo does not converge upon other definite forms, but separates itself from them. # The '''embryo''' of a higher animal form never resembles the '''adult''' of another animal form, such as one less evolved, but only its embryo.
Summary:
Please note that all contributions to Niidae Wiki may be edited, altered, or removed by other contributors. If you do not want your writing to be edited mercilessly, then do not submit it here.
You are also promising us that you wrote this yourself, or copied it from a public domain or similar free resource (see
Encyclopedia:Copyrights
for details).
Do not submit copyrighted work without permission!
Cancel
Editing help
(opens in new window)
Search
Search
Editing
Karl Ernst von Baer
(section)
Add topic