INTERNAL STRUCTURE OF PLANTS. 
5 
of it, that it may have exuded from the first tissue, but that it 
is not homogeneous with it. In this respect he distinguishes 
the second tissue from the first; and since the cells of this 
first tissue resemble foam, being only more consistent, he 
terms the first tissue “ aphrostase the second, because it 
accompanies, and, as it were, conducts the vessels, “ hege- 
mon.” A division, or fissure, which he calls “ cunice,” 
separates, in trees, the bark from the internal part, or from 
the “ endophyte” as he terms it. The inner part, however, 
does not consist of a single part, but of the pith, and that 
which is called wood, but which does not always deserve this 
name, as it is frequently very soft in herbs. The author 
therefore terms it “ endostere,” because it is at all events 
firmer than the surrounding part. He now proceeds to ex- 
amine the origin of the so-termed “ prolongemens medullaires,” 
and says of them, that they originate from the “ tissue aphros- 
tasien,” that they also continually get smaller, and that the 
vascular bundles which have grown up, thicken, at last only 
leaving a trace of them. He therefore terms them “ isthmes 
aphrostasien,” or briefly “ isthmes.” The consideration of a 
transverse section in the stem of a bramble {Ruhus fruticosus) 
leads him to the adoption of a third tissue, which he terms 
“ proxyle,” distinguishing it by the circumstance, that it con- 
sists of prismatic or cylindrical fibres (filets) of an indefinite 
length. He examines it from its first origin, and finds that it 
also consists at first of a cambium, so that each of the three 
tissues has its own peculiar cambium. These tissues are very 
often intermixed, and he terms such a mixture, which is pro- 
duced from an effusion of the cambium “ proxylaire,” into 
another already formed tissue, an “ adelome.” These are 
the principal contents of the treatise. 
It is gratifying to see, how an observer, without regarding 
that which others have done before him, nevertheless hits 
upon the best arrangement. The three kinds of cellular 
tissue, as determined by the author, certainly deserve to be 
distinguished. The first is that cellular tissue (called aph- 
rostases'' by the author), which constitutes the basis of the 
whole stem, or rather of the whole plant, and which always 
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