The Marcus Beck Laboratory reports.

Date:
1914
Catalogue details

Licence: In copyright

Credit: The Marcus Beck Laboratory reports. Source: Wellcome Collection.

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    It was impossible, unfortunately, to get the whole of this cell completely in focus. No. 5 shows a similar parent cell (lower magnification) with two daughter red cells within it. No. 4 shows a mass of parent amoeboid cells, each containing from one to six nuclei. The cells are connected with each other by protoplasmic processes. This photograph resembles markedly fig. 30, p. 30, in Schafer’s “ Essentials of Histo- logy ” (1910), in which is shown the development of blood corpuscles in the vascular area of the guinea-pig. Photomicrographs 6 to 9 (growth in vitro of blood-forming tissues of an embryonic chick three days old) show the formation of nucleated red cells in pairs, threes and fours; some of these form at the margin in the shape of a nucleated crescent. No. 10 is taken from a Giemsa-stained smear of the spleen of a sixteen- day-old chick embryo, and shows in the centre a cell mass containing six nuclei. This I believe is a parent colourless cell about to form six daughter nucleated red cells. No. 11, from a Giemsa-stained smear (spleen puncture) from a case of human splenic anaemia, shows a nucleated red cell (N), and also one in the process of mitosis (M). It is interesting to note that the human nucleated red cell is about exactly the same size as the nucleated red cells of the chick as shown in photomicrograph 10 taken at an identical magnification, and that the non-nucleated human red cells are much smaller than the nucleated forms. (b) The Midtiplication of Nucleated Bed Cells by Simple Division.—It is well known that nucleated red cells can multiply by simple mitosis. This process has been fully observed in the blood of newts and a cinematographic film of the phenomenon has even been taken by Dr. Comandon (Pathe Freres). I am in doubt as to whether the photomicrographs 6 to 9, Plate II, represent simply the division of already existing nucleated red cells of the chick or whether they show the production of daughter red cells from the original amoeboid parent cells. If they represent the former then the photographs would appear to indicate that a nucleated red cell is capable of dividing into two, three and four red cells. (IV) Observations on Bone-marrow Cultures (Embryonic Chick). In these the development of red cells was similar to that already described under the spleen cultures. Foot (1913) made observations on the cultivation in vitro of bone-marrow of chicks, more especially with regard to the development of the leucocytes. He does not appear to