E X P E R I M E N T S ON EMBRYONIC AORTIC ARCHES 335
aortic arch. Finally, it may be mentioned that Vogel and McClenahan
(1951) occluded the carotid arteries of 6-day-old chick embryos by
electrocauterization, and obtained anencephaly.
b. Amphibia and Fishes
Figge (1934) ligated ventral parts of the pulmonary arches in
Ambystoma tigrinum (with the aim of imitating the vascular pattern
of Necturus) and prevented its metamorphosis. Ichikawa (1931, 1932)
excised the 4th and 3rd aortic arches in Hynobius retardatus and followed
the substitutional changes in other arches after completed metamorphosis. Alphonse and Baumann (1934) succeeded in eliminating
some of the aortic arches in tadpoles of Bufo vulgar is with thyroxine.
Baumann and Poster (1936) used the same method in salmon embryos.
Finally Millard (1945) destroyed aortic arches in tadpoles of Xenopus;
the loss of one or both of the 3rd arch and a pulmocutaneous (6th aortic)
arch led to death.
2. Experiments on the Heart
a. Birds
Many experiments have been performed at the double heart tube
stage with the intention either of elucidating the developmental
mechanics of the heart or of preventing the fusion of the tubes (e.g.,
Waddington, 1932; Szepsenwol, 1934; Waddington and Cohen, 1936).
Recently, Le Douarin (1960) after local irradiation with X-rays
observed cardiac anomalies, especially the transposition of the aorta
into the right ventricle.
b. Amphibia
The number of publications dealing with amphibia is much larger.
The whole heart tube or its parts have been excised, rotated, exchanged
(homo- and heteroplastically), fused, etc., before the onset of circulation
(Stöhr, 1924a, b, 1925, 1927; Ekman, 1925; Copenhaver, 1926, 1930,
1939, 1945; Bacon, 1945).
3. Methods of Local Intervention on Chosen Aortic Arches and /or the
Heart-loop
Strictly local intervention on any chosen aortic arch (Rychter, 1957,
1961a, b) or on any part of the heart loop (Rychter and Lemez, 1958a,
b, 1959a, b, c, 1960a, b) or on aortic arches and the heart loop simultaneously (Rychter and Lemez, 1960b, 1961b) was attained by using
the clip method and its variants. The method was first used to suppress
yolk sac veins of chick embryos (Rychter and Lemez, 1956). In principle
the task is to introduce a microclip into the branchial clefts and to
compress gently the branchial arch including the contained aortic arch
aortic arch. Finally, it may be mentioned that Vogel and McClenahan
(1951) occluded the carotid arteries of 6-day-old chick embryos by
electrocauterization, and obtained anencephaly.
b. Amphibia and Fishes
Figge (1934) ligated ventral parts of the pulmonary arches in
Ambystoma tigrinum (with the aim of imitating the vascular pattern
of Necturus) and prevented its metamorphosis. Ichikawa (1931, 1932)
excised the 4th and 3rd aortic arches in Hynobius retardatus and followed
the substitutional changes in other arches after completed metamorphosis. Alphonse and Baumann (1934) succeeded in eliminating
some of the aortic arches in tadpoles of Bufo vulgar is with thyroxine.
Baumann and Poster (1936) used the same method in salmon embryos.
Finally Millard (1945) destroyed aortic arches in tadpoles of Xenopus;
the loss of one or both of the 3rd arch and a pulmocutaneous (6th aortic)
arch led to death.
2. Experiments on the Heart
a. Birds
Many experiments have been performed at the double heart tube
stage with the intention either of elucidating the developmental
mechanics of the heart or of preventing the fusion of the tubes (e.g.,
Waddington, 1932; Szepsenwol, 1934; Waddington and Cohen, 1936).
Recently, Le Douarin (1960) after local irradiation with X-rays
observed cardiac anomalies, especially the transposition of the aorta
into the right ventricle.
b. Amphibia
The number of publications dealing with amphibia is much larger.
The whole heart tube or its parts have been excised, rotated, exchanged
(homo- and heteroplastically), fused, etc., before the onset of circulation
(Stöhr, 1924a, b, 1925, 1927; Ekman, 1925; Copenhaver, 1926, 1930,
1939, 1945; Bacon, 1945).
3. Methods of Local Intervention on Chosen Aortic Arches and /or the
Heart-loop
Strictly local intervention on any chosen aortic arch (Rychter, 1957,
1961a, b) or on any part of the heart loop (Rychter and Lemez, 1958a,
b, 1959a, b, c, 1960a, b) or on aortic arches and the heart loop simultaneously (Rychter and Lemez, 1960b, 1961b) was attained by using
the clip method and its variants. The method was first used to suppress
yolk sac veins of chick embryos (Rychter and Lemez, 1956). In principle
the task is to introduce a microclip into the branchial clefts and to
compress gently the branchial arch including the contained aortic arch