THE BLOOD OF CHICK EMBRYOS
209
From data on erythrocyte number per cu.mm, haemoglobin content,
and haematocrit values it is possible to calculate the characteristics of
the 'average erythrocyte', namely, erythrocyte volume, amount of
haemoglobin per cell, and concentration of haemoglobin in the cytoplasm (Fig. 3). There are only two studies (O'Connor, 1952a; Rychter
et al., 1955a) which cover the entire incubation period. O'Connor
obtained values by measuring individual cells, while the latter authors
calculated their values from the basal data. Values for cell volume are
in close agreement, but O'Connor (1952a) found much higher haemoglobin concentration and haemoglobin content per cell than the others.
This could be due either to the sampling of more mature erythrocytes or
to the use of different haemoglobin standards.
Generally, the graph reflects the gradual development of the red blood
picture towards a mature state and the changing ratio of primitive and
definitive red blood cells in particular.
Proof was given of the differences in the volume of average definitive
erythrocytes of embryos (about 130cu./z) and in adult hens (about
103 cu.jit) (Rychter et al., 1955a). The embryonic definitive erythrocytes
may rightly be called, therefore, macrocytes (as distinguished from
megalocytes, Ε I). The primitive erythrocyte volume decreases from
about 800 cu./x on the 2nd day to about 400-500 cu./x on the 5th to 6th
day (Rychter, 1955). The latter value might be taken as their mature
volume, which exceeds by about 3-5 times that of the embryonic
definitive erythrocytes.
3. Miscellaneous Observations Relating to Chick Embryo
Erythrocytes
Various cytoplasmic organelles, especially the mitochondria and
Golgi apparatus, have been studied in supravitally stained young
erythrocytes (Meves, 1908; Fananâs, 1912; Sabin, 1921; Doan et al.,
1925; Sugiyama, 1926; Takagi, 1931, 1932; Dawson, 1936). The rapid
changes in size and position of mitochondria in explanted young
primitive red cells were detected by microcinematography by Borghese
etal. (1954b).
Elias and Sandor (1960) found that the resistance of chick embryo
erythrocytes to haemolysis was practically constant between the 11th
day of incubation and the 32nd postembryonic day. There are no
differences in the sizes of the cells or the nuclei of embryonic and adult
erythrocytes of large and dwarf fowl breeds (Keller, 1933). Ascorbic
acid, which is not detectable at 48 hours of incubation in primitive red
blood cells, is present in appreciable amount 1 day later (Girelli, 1957).
As might be expected the incorporation of Fe-59 into basophilic and
polychromatophilic elements was higher than into orthochromatic red
blood cells (Tamburino and Salera, 1957). Correspondingly, the uptake
209
From data on erythrocyte number per cu.mm, haemoglobin content,
and haematocrit values it is possible to calculate the characteristics of
the 'average erythrocyte', namely, erythrocyte volume, amount of
haemoglobin per cell, and concentration of haemoglobin in the cytoplasm (Fig. 3). There are only two studies (O'Connor, 1952a; Rychter
et al., 1955a) which cover the entire incubation period. O'Connor
obtained values by measuring individual cells, while the latter authors
calculated their values from the basal data. Values for cell volume are
in close agreement, but O'Connor (1952a) found much higher haemoglobin concentration and haemoglobin content per cell than the others.
This could be due either to the sampling of more mature erythrocytes or
to the use of different haemoglobin standards.
Generally, the graph reflects the gradual development of the red blood
picture towards a mature state and the changing ratio of primitive and
definitive red blood cells in particular.
Proof was given of the differences in the volume of average definitive
erythrocytes of embryos (about 130cu./z) and in adult hens (about
103 cu.jit) (Rychter et al., 1955a). The embryonic definitive erythrocytes
may rightly be called, therefore, macrocytes (as distinguished from
megalocytes, Ε I). The primitive erythrocyte volume decreases from
about 800 cu./x on the 2nd day to about 400-500 cu./x on the 5th to 6th
day (Rychter, 1955). The latter value might be taken as their mature
volume, which exceeds by about 3-5 times that of the embryonic
definitive erythrocytes.
3. Miscellaneous Observations Relating to Chick Embryo
Erythrocytes
Various cytoplasmic organelles, especially the mitochondria and
Golgi apparatus, have been studied in supravitally stained young
erythrocytes (Meves, 1908; Fananâs, 1912; Sabin, 1921; Doan et al.,
1925; Sugiyama, 1926; Takagi, 1931, 1932; Dawson, 1936). The rapid
changes in size and position of mitochondria in explanted young
primitive red cells were detected by microcinematography by Borghese
etal. (1954b).
Elias and Sandor (1960) found that the resistance of chick embryo
erythrocytes to haemolysis was practically constant between the 11th
day of incubation and the 32nd postembryonic day. There are no
differences in the sizes of the cells or the nuclei of embryonic and adult
erythrocytes of large and dwarf fowl breeds (Keller, 1933). Ascorbic
acid, which is not detectable at 48 hours of incubation in primitive red
blood cells, is present in appreciable amount 1 day later (Girelli, 1957).
As might be expected the incorporation of Fe-59 into basophilic and
polychromatophilic elements was higher than into orthochromatic red
blood cells (Tamburino and Salera, 1957). Correspondingly, the uptake