THE BLOOD OF CHICK EMBRYOS
199
embryos. Guinea pig serum was injected on the 12th day of incubation
into a chorioallantoic vein by Polk et al. (1938). Methods for intravenous
injection of microbiological material were described also by Eichhorn
(1940), Lee et al. (1946), Beveridge and Burnet (1946), and Dosch (1954).
Suspensions of living cells, both tumourous and normal, were injected
intravenously and their dissemination by the vascular route was traced
by Bender et al. (1949) and Weiss and Andres (1952), respectively.
Methods for cross-transfusions of chick embryo blood were described by
Haâek (1953a, b) and Terasaki and Cannon (1957); and a method for
continuous infusion of substances into the chorioallantoic circulation is
given by Drachman and Coulombre (1962).
When referring to published data in the following review, the reader
must bear in mind that various breeds of chicken, different amounts of
material, and, especially, different incubation temperatures and incubation conditions were used by the various authors, so that a difference
of 1 day, or sometimes even of 2 days, might be within the limits of
variability of the embryonic material and methods employed.
A. Erythrocytes
1. Morphology and Differential
Count
There is general agreement nowadays that the first erythrocytes
formed in the yolk sac in vertebrate embryos represent a primitive
(megaloblastic) series differing from the definitive (normoblastic) series
characteristic of older embryos and adults (Copenhaver, 1955). The
same agreement is generally held in respect of the nature of chick
embryo erythrocytes, apart from the oldest references (Hewson, 1773;
Prévost and Dumas, 1824; Jones, 1846; Metschnikow, 1867—quoted by
Giglio-Tos, 1897). Boccardi (1886), and most later authors who have
studied erythrocytes during the incubation period (Giglio-Tos, 1897;
Sugiyama, 1926; MalenSek, 1932; Dawson, 1936; Fennell, 1947;
Sandreuter, 1951; Alexander and Schjeide, 1953; Lemez, 1953, 1958;
Lemez and Rychter, 1956), have agreed that the primitive erythrocytes
(Ε I) and definitive erythrocytes (Ε II) (or the megaloblastic and
normoblastic series) belong to two separate cell lines without any
transitional forms. However, Dantschakoff in her earliest paper (1908a),
and Slonimski (1938), studying histological sections, claimed to have
observed transitional forms between the primitive and definitive
elements. Price-Jones (1910) also made this claim. Engel (1895) originally
held that primitive erythrocytes are mother-cells of the definitive ones,
but later changed his opinion (Engel, 1915). Since her earliest paper
mentioned above, Dantschakoff (1908b, 1909) has always distinguished
precisely the elements of both lines with no transitional forms.
199
embryos. Guinea pig serum was injected on the 12th day of incubation
into a chorioallantoic vein by Polk et al. (1938). Methods for intravenous
injection of microbiological material were described also by Eichhorn
(1940), Lee et al. (1946), Beveridge and Burnet (1946), and Dosch (1954).
Suspensions of living cells, both tumourous and normal, were injected
intravenously and their dissemination by the vascular route was traced
by Bender et al. (1949) and Weiss and Andres (1952), respectively.
Methods for cross-transfusions of chick embryo blood were described by
Haâek (1953a, b) and Terasaki and Cannon (1957); and a method for
continuous infusion of substances into the chorioallantoic circulation is
given by Drachman and Coulombre (1962).
When referring to published data in the following review, the reader
must bear in mind that various breeds of chicken, different amounts of
material, and, especially, different incubation temperatures and incubation conditions were used by the various authors, so that a difference
of 1 day, or sometimes even of 2 days, might be within the limits of
variability of the embryonic material and methods employed.
A. Erythrocytes
1. Morphology and Differential
Count
There is general agreement nowadays that the first erythrocytes
formed in the yolk sac in vertebrate embryos represent a primitive
(megaloblastic) series differing from the definitive (normoblastic) series
characteristic of older embryos and adults (Copenhaver, 1955). The
same agreement is generally held in respect of the nature of chick
embryo erythrocytes, apart from the oldest references (Hewson, 1773;
Prévost and Dumas, 1824; Jones, 1846; Metschnikow, 1867—quoted by
Giglio-Tos, 1897). Boccardi (1886), and most later authors who have
studied erythrocytes during the incubation period (Giglio-Tos, 1897;
Sugiyama, 1926; MalenSek, 1932; Dawson, 1936; Fennell, 1947;
Sandreuter, 1951; Alexander and Schjeide, 1953; Lemez, 1953, 1958;
Lemez and Rychter, 1956), have agreed that the primitive erythrocytes
(Ε I) and definitive erythrocytes (Ε II) (or the megaloblastic and
normoblastic series) belong to two separate cell lines without any
transitional forms. However, Dantschakoff in her earliest paper (1908a),
and Slonimski (1938), studying histological sections, claimed to have
observed transitional forms between the primitive and definitive
elements. Price-Jones (1910) also made this claim. Engel (1895) originally
held that primitive erythrocytes are mother-cells of the definitive ones,
but later changed his opinion (Engel, 1915). Since her earliest paper
mentioned above, Dantschakoff (1908b, 1909) has always distinguished
precisely the elements of both lines with no transitional forms.