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OBSERVATIONS ON THE NUCLEOLI IN THE CELLS OF HYDRA FUSCA
Author(s) -
Walker C. E.,
Embleton Alice L.
Publication year - 1908
Publication title -
quarterly journal of experimental physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.925
H-Index - 101
eISSN - 1469-445X
pISSN - 0370-2901
DOI - 10.1113/expphysiol.1908.sp000020
Subject(s) - nucleolus , endoderm , ectoderm , nucleus , cytoplasm , biology , microbiology and biotechnology , mitosis , lernaean hydra , cell division , cell nucleus , cell , embryo , genetics , embryonic stem cell , embryogenesis , gene
The phenomenon here recorded seems to be something quite apart from anything connected with cell division, whether mitotic or amitotic; indeed, it is only to be observed in cells that are in the vegetative condition. The probability that it is intimately connected with, and dependent upon, metabolism taking place in the nucleus, is very strong. While it is readily observed in almost all the cells of the endoderm, it can be followed only to a very limited extent in the cells of the ectoderm. The processes connected with digestion are carried out by the cells of the endoderm. It would therefore appear probable that the kind of metabolism in the nucleus that is connected with digestion produces this phenomenon in a more striking manner, and more frequently, than is the case with the nuclear metabolism taking place in the cells of the ectoderm. The rapid and very marked change in the staining reaction of the nucleolus as it passes into the cytoplasm, suggests that some important chemical or physical change takes place in the contents at this time. Similar changes have been observed in the nucleoli of nerve‐ganglion cells. It seems probable that the bodies here described as extruded nucleoli have been frequently described as food particles. But we would point out that the structures here dealt with are apparently in process of disintegration at the periphery of the cell, become more defined in the neighbourhood of the nucleus, and are found in their most definite form and in process of active multiplication within the nucleus itself.