On the Multinuclear Cells of some Grasses. 



By Rudolf Beer. 



Plates I. and II. 



A few years ago we unhesitatingly affirmed that the cell was. the 

 ultimate unit of the animal or vegetable body. At the present day we 

 do indeed continue to uphold the cell as the elementary structural 

 component of the living body, but not without some misgivings, since 

 recent research has made us acquainted with various phenomena which 

 we find it difficult to reconcile with this conception. 1 



The work of a large band of investigators has shown that in a 

 number of tissues, both animal and vegetable, the intercellular wall 

 forms by no means so sharp a separation between the protoplasmic 

 bodies as was formerly believed. In these cases the refined methods of 

 modern research have revealed to us a system of delicate fibrils of pro- 

 toplasm which pass through perforations in the cell-wall, and directly 

 connect neitdibourino; cell-bodies. 



Further cause for uncertainty has been given by the discovery of 

 multinuclear cells, i.e. cell-cavities which contain a single protoplasmic 

 body in which are included a plurality of nuclei. Among the lower 

 plants we meet with whole groups of organisms (e.g. Siphoneae) in 

 which the body shows no septation into cells, although it is frequently 

 both large and highly differentiated. 



To use Sachs' phrase, the bodies of these plants are " non-cellular," 

 for they contain a large, continuous mass of protoplasm which is 

 studded with innumerable nuclei (15 2 and 16). 



The embryo-sac of the higher plants, at one time of its existence, 

 contains a large number of nuclei (8) ; the laticiferous tubes of a num- 

 ber of plants (Euphorbieae, etc.) are also multinuclear (18); the 

 elongated bast-cells (18), the cells of the suspensor of some Leguminosae 

 (6), the older internode cells of Characeae (10), the older parenchyma 



1 A full explanation of the terms used in this paper will be found in two articles, 

 by Mr. Hill and myself, which were published in previous numbers of this journal 

 (7 and 1). 



2 These numerals refer to papers, etc., quoted at end of article. 



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