Open AccessThe origin of erythrocytes in herring ( Clupea harengus )
Author(s) -
Chris John
Publication year - 1932
Publication title -
proceedings of the royal society of london. series b, containing papers of a biological character
Language(s) - English
Resource type - Journals
eISSN - 2053-9185
pISSN - 0950-1193
DOI - 10.1098/rspb.1932.0014
Subject(s) - anatomy , clupea , somite , biology , mesenchymal stem cell , microbiology and biotechnology , embryo , process (computing) , embryogenesis , herring , fishery , fish <actinopterygii> , computer science , operating system
The origin of erythrocytes in fishes presents an almost unique problem on account of the different methods of their formation and the varying stages of development at which they are found in the circulation. The general opinion would seem to indicate that all blood cells arise from mesenchymal type of cells arise from mesenchymal type of cells at at very early period in the embryonic development. For a precise comprehension of the development of the blood and vascular system it is only necessary to consider the opinions of some of the recent workers on the subject. According to Swaen and Brachet (1901) the mesoblast in the posterior half of the embryo consists of an inner primary somite portion of the primary lateral plate part a adjacent to the somites divides off and forms a mass of intermediate cells. The primary lateral plate grows towards the median line pushing its way beneath the somites to form a keel-shaped mass which cuts off the somites from the peritonial cavity. This keel-shaped mass of cells unites with similar cells from the opposite side, resulting in a large median group of intermediate cells. This same process takes place in the posterior region so that the intermediate cell mass becomes a continuous layer. From this definite region of the mesoblast called the intermediate cell mass originates the heart, vasular system, and the blood in the embryo. Though the mesodermal origin of the vascular system and the blood cells is generally accepted, the exact process of the formation and development of the different kinds of blood cells is a highly disputed problem. Some of the earlier workers have maintained that all the different kinds of blood cells originate from the same types of mesenchymal cells. According to this view, the mesenchymal cells change into stem inother cells which, on the one hand, give rise to leucocytes and on the other, to typical erythrocytes. This point could not be verified by any study of normal material, as circulation of the embryonic fluid is established very early before the appearance of blood corpuscles, so that when the latter are formed, they are swept into the circulating current and carried to all parts of the body. This necessarily makes the study of the origin of blood cells a rather difficult problem.