vegi:table organization. 57 



is a highly magnified representation of the simplest 

 form of these vesicles.* But they generally ad- 

 here together more closely, composing by their 

 union a species of vegetable cellular tissue, which 

 may be regarded as the basis or essential compo- 

 nent material of every organ in the plant. This 

 cellular structure is represented in figures 4 and 5, 

 as it appears in the Fucus vesiculosus ; the first being 

 a horizontal, and the second a vertical section of 

 that plant.t The size of these cells differs consi- 

 derably in different instances. Kieser states that 

 the diameter of each individual cell varies from the 

 330th to the 55th part of an inch ; so that from 



olus, is retained witliin the cell to which it gave origin; and, with 

 the aid of a good microscope, it may still be seen either loose within 

 the cavity of the cell, or adhering to its sides. But by the time the 

 cell has grown to its full size, the nucleus has generally disappeared, 

 having apparently dissolved itself in the fluid contents of the cell. 

 Moreover, the cell never shows any trace of spiral fibres, previously 

 to its having attained its complete growth, and before the absorption 

 of the cytoblast. 



A new set of nuclei, again, are seen to form, either within the 

 cell, or in the intercellular spaces ; and they give rise to a train of 

 phenomena exactly similar to that already described ; and thus new 

 cells, furnishing the fabric of growth, are supplied, and their number 

 multiplied in continued succession. 



The frequent presence of the nucleus which formed the vegetable 

 cells had already attracted the notice of botanists; and its import- 

 ance was specially recognised and pointed out by Mr. Robert 

 Brown, in his masterly researches on the Orchidece : but the merit 

 of the discovery of its being the germ of the vegetable cell is due to 

 Schleiden. See his memoirs in Miiller's Archiv. t'iir Anatomie und 

 Physiologie, Part II. 1838; a translation of which memoir will be 

 found in R. Taylor's Scientific Memoirs, Vol. II. Part vj. p. 281. 



* These cells are well represented in the engravings which illus- 

 trate Mr. Slack's memoir on the elementary tissue of plants, con- 

 tained in the 49lh volume of the Transactions of the Society of Arts. 



t De Candolle, Organographie Vegetale. 



