Paper - Six normal and complete presomite human ova

From Embryology
Embryology - 19 Jun 2024    Facebook link Pinterest link Twitter link  Expand to Translate  
Google Translate - select your language from the list shown below (this will open a new external page)

العربية | català | 中文 | 中國傳統的 | français | Deutsche | עִברִית | हिंदी | bahasa Indonesia | italiano | 日本語 | 한국어 | မြန်မာ | Pilipino | Polskie | português | ਪੰਜਾਬੀ ਦੇ | Română | русский | Español | Swahili | Svensk | ไทย | Türkçe | اردو | ייִדיש | Tiếng Việt    These external translations are automated and may not be accurate. (More? About Translations)

Brewer JI. and Fitzgerald JE. Six normal and complete presomite human ova. (1937) Amer. J. Obstet. Gynecol, 34: 210-224.

Online Editor  
Mark Hill.jpg
This historic 1937 meeting abstract by Brewer and Fitzgerald describes development of the early human embryos, Carnegie stage 7. Note the historic terminology of "ova" for this early stage of development.

By the same author: Brewer JI. A normal human ovum in a stage preceding the primitive streak (The Edwards-Jones-Brewer ovum). (1937) Amer. J Anat., 61: 429-481.

Brewer JI. A human embryo in the bilaminar blastodisc stage (The Edwards-Jones-Brewer ovum). (1938) Contrib. Embryol., Carnegie Inst. Wash. Publ. 496, 27: 85-93.
Modern Notes:

Stage 7 Links: Week 3 | Gastrulation | Lecture | Practical | Carnegie Embryos | Category:Carnegie Stage 7 | Next Stage 8
  Historic Papers: 1923 head-process | 1933 tubal | 1940 | 1949
Historic Disclaimer - information about historic embryology pages 
Mark Hill.jpg
Pages where the terms "Historic" (textbooks, papers, people, recommendations) 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, interpretations and recommendations may not reflect our current scientific understanding.     (More? Embryology History | Historic Embryology Papers)

Six Normal and Complete Presomite Human Ova

J. Brewer, M.D., Ph.D., And James E. Fitzgerald, M.D., Chicago, Ill.

From the Department of Obstetrios Laboratory of, St. L&e’s Hospital, Gynecology of Northwestern and Gynecology and the Henry Baird and the Department of Obstetrics and University Medical School

  • The Prize Award paper, read at the Eighth Annual Meeting of the Central Association of Obstetricians and Gynecologists, Detroit, Mich., October 15 to 17, 1936.

Aided by a grant from Mrs. Emmons Blaine and from the Rockefeller Institute to the University of Chicago.


The possession of six perfectly preserved, stained, and serially sectioned presomite human ova of different ages in one laboratory affords excellent material for detailed study of implantation, early placentation, and embryonic development. There are approximately 75 presomite human ova reported in the world literature. The majority, however, are of little value. Only 30 have sufficient data and are normal enough to permit the drawing of conclusions. Only a few are anatomically complete and sectioned favorably. Interpretation of the findings have been reported by such a diversified group of workers that uniformity is lacking. To obviate this, Grosser, Streeter, Teacher, Bryce, Florian and Hill, and others have made collective studies of all the presomite ova to which they have had access.

Our group comprises six presomite ova, all of which were obtained by hysterectomy. In none was there any abnormality of the pregnancy. This is important in considering the actual stage of development. All were fixed within ten minutes after clamping the uterine blood supply. Each was sectioned and arranged serially. Four were oriented so that the embryonic disc was cut in cross-section and two were cut sagittally, There were no sections lost in any of the specimens. Various fixing solutions and stains were used. One ovum, the Jones-Brewer I, is the youngest human ovum to have cytologic methods applied to placentation. The Edwards-Jones-Brewer specimen is the youngest normal and anatomically complete ovum to be reported in the United States.

The latter is particularly adapted to a study of implantation because all sections include the entire thickness of the endometrium and a portion of myometrium. This makes possible a complete study of the vascular phenomena. Trophoblastic activity is equally well investigated in this ovum and the next youngest of our group, the Jones-Brewer I ovum.

Vascular Phenomena

The vascular changes in the endometrium of early pregnancies are identical to those phenomena in the normal menstrual cycle (Brewer).

Cite this page: Hill, M.A. (2024, June 19) Embryology Paper - Six normal and complete presomite human ova. Retrieved from

What Links Here?
© Dr Mark Hill 2024, UNSW Embryology ISBN: 978 0 7334 2609 4 - UNSW CRICOS Provider Code No. 00098G