All transitions are found between such forms and typical tracheids.
The fibres belong to the same n,orpholcgical category as the parenchyma, various transitions being found between them; thus there may be thin-walled cells of the shape of fibres, or ordinary fibres may be divided into a number of superposed cells.
By a natural series of transitions the gift theory became transformed, in the minds of the sacrificers, into the homage theory, which again passed by an easy transition into the renunciation theory.
From these we can pass by gradual transitions in two directions, viz.
In 1872, Hoppe-Seyler (1825-1895) gave a new beginning to our knowledge of the chemistry of secretion and of excretion; and later students have increased the range of physiological and pathological chemistry by investigations not only into the several stages of albuminoid material and the transitions which all foodstuffs undergo in digestion, but even into the structure of protoplasm itself.