File:Morgan 1925 fig31.jpg

From Embryology
Original file(953 × 897 pixels, file size: 208 KB, MIME type: image/jpeg)

Fig. 31. Diagram to show stages in fertilization of an egg by a spermatozoon

The three polar bodies lie at one pole, and the spermatozoon is represented as entering near the opposite side of the egg in 1 and 2. The head of the sperm swells up and moves towards the egg-nucleus, that has reformed after the polar bodies have been given off. A centrosome forms near the sperm-nucleus. It divides into two centrosomes, which begin to se])arate as a central spindle appears between them. Around each centrosome astral rays develop. The two nuclei come together in the middle of the egg to become the segmentation nucleus. A spindle develops around the nucleus.

Historic Disclaimer - information about historic embryology pages 
Mark Hill.jpg
Pages where the terms "Historic Textbook" and "Historic Embryology" appear on this site, and sections within pages where this disclaimer appears, indicate that the content and scientific understanding are specific to the time of publication. This means that while some scientific descriptions are still accurate, the terminology and interpretation of the developmental mechanisms reflect the understanding at the time of original publication and those of the preceding periods, these terms and interpretations may not reflect our current scientific understanding.     (More? Embryology History | Historic Embryology Papers)

Morgan (1925) Evolution and Genetics: 1 Different Kinds of Evolution | 2 Four Great Historical Speculations | 3 Evidence for Organic Evolution | 4 Materials of Evolution | 5 Mendel's Two Laws of Heredity | 6 Chromosomes and Mendel’s Two Laws | 7 Linkage Groups and the Chromosomes | 8 Sex-Linked Inheritance | 9 Crossing-over | 10 Natural Selection and Evolution | 11 Origin of Species by Natural Selection | 12 Non-Inheritance of Acquired Characters | 13 Human Inheritance | Figures


Morgan, T. H. (1925). Evolution and genetics. Princeton: Princeton University Press.

Cite this page: Hill, M.A. (2019, August 21) Embryology Morgan 1925 fig31.jpg. Retrieved from

What Links Here?
© Dr Mark Hill 2019, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G

File history

Click on a date/time to view the file as it appeared at that time.

current08:22, 20 October 2014Thumbnail for version as of 08:22, 20 October 2014953 × 897 (208 KB)Z8600021 (talk | contribs)
08:22, 20 October 2014Thumbnail for version as of 08:22, 20 October 20141,000 × 1,420 (354 KB)Z8600021 (talk | contribs)
  • You cannot overwrite this file.