Talk:Embryology History - Chester Heuser

From Embryology

Streeter, G. L. (Prepared for publication by C. H. Heuser and G. W. Corner.) Developmental horizons in human embryos. Description of age groups xix, xx, xxi, xxii, and xxiii, being the fifth issue of a survey of the Carnegie Collection. Carnegie Inst. Wash. Pub. 592, Contr. to Embryol., vol. 34, pp. 165-196 (1951).

Developmental horizons in human embryos: Age groups xi to xxiii. Embryology Reprint Volume II, Carnegie Inst. Wash. (951).

Dr. Chester H. Heuser

Carnegie Institution of Washington Year Book No. 51 July, 1951 - June 30, 1952 With Administrative Reports Through December 12, 1952 Carnegie Institution Of Washington Washington, D. C. 1952

Dr. Chester H. Heuser, who retired on August 31, 1950 after twenty-nine years of continuous service, was appointed a Research Associate, Department Of Embryology Baltimore. During the summer of 1951 he spent two months at the Department of Embryology working on human embryos in preparation for his proposed descriptive catalogue of the earlier stages (i to x) which were not included in the series "Developmental Horizons in Human Embryos" begun by the late Dr. George L. Streeter.

Department Of Embryology Baltimore, Maryland George W. Corner, Director


Early human embryos. During his stay at the laboratory in July and August 1951 Dr. Chester H. Heuser began intensive work on the earliest embryos in the Carnegie Collection, that is to say those of horizons i to x of the Streeter classification, covering the age span from ovulation to 24 days. The collection now includes 65 specimens within this age span, a large proportion of which were obtained by Dr. Arthur T. Hertig and Dr. John Rock. About 35 of these are normal and well preserved and are therefore suitable for inclusion in the Horizons series which Dr. Heuser is preparing. As reported in recent Year Books, several extremely early embryos have recently been added. From the standpoint of the comparative embryologist a most valuable part of the series is that from 7 to 18 days, when the embryo is securing its attachment to the mother and when it passes through those primitive steps of organization which are common to all vertebrates, including the processes of gastrulation, formation of the amniotic duct, of the allantois, the notochord and chorda canal, etc. Upon such basal embryonic processes the biologist must depend as part of his evidence for determining evolutionary relationships in the animal kingdom. The relatively large number of specimens available in the Collection makes it possible to follow them in man more closely than before.

About 6 early embryos, cut by Dr. Heuser, were added to the available sectioned material. At the instance of Dr. G. W. Bartelmez, about 12 early human embryos, obtained and prepared by him personally during his long connection with the University of Chicago, were donated by the Department of Anatomy of that institution. These embryos, some of which are of presomite age, constitute an important addition to the resources of the Department of Embryology. Several of them are superbly preserved.