Abstract
The typical animal or vegetable cell is now universally held to consist of a protoplasmic body, either naked or enclosed in a cell membrane and containing, as its most essential constituent, a single nucleus. This view as to the uninucleate character of the vegetable cell was first definitely formulated by Nägeli in 1844. A few well-defined exceptions to this rule, such as pollen grains, embryo sacs, etc., were recognised by Nägeli himself, and during the three-quarters of a century which has elapsed since the publication of his work, several other instances of multinucleate cells have been observed by Schmitz, Treub, Johow, Strasburger, Grant, and others. These cases, in which a plurality of nuclei was seen to occur in the cell, were however regarded as isolated exceptions to an otherwise universal rule, and of no general significance. In 1914 Dr. McLean observed cells with more that one nucleus in the tissues of certain water plants, while in 1915 Miss Prankerd published an account of her researches on multinucleate cells. She recorded the occurrence of multinucleate cells in 36 species of plants “widely separated in habit, habitat, and systematic position,” including both Vascular Cryptogams and Angiosperms. Miss Prankerd considers, like nearly all of those who have written upon this subject, that the plurality of nuclei arises by amitosis With regard to the ultimate fate of the nuclei, she does not believe it probable either that all the nuclei but one degenerate in each cell, or that they fuse with one another. She is inclined to suppose that walls may ultimately be formed between the daughter nuclei which have arisen by amitosis.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have