118 
Osborne^ on the Wheat Plant. 
I will now briefly remark upon those beautiful structures 
known as scalariform^ spiral_, annular^ and dotted fibre. In 
the leaf of the wheat I find the true spiral^— the annular^ the 
scalariform ; in the roots I find only the latter^ with an 
accompaniment of dotted tissue. At the very earliest stage 
at which; by dissection^ a view can be obtained of leaf and 
root formation^ the fibres proper to each are discovered, the 
spiral completely formed, the scalariform in active formation ; 
the former turning upwards to the leaves, the latter separating 
into bundles and going downwards to the roots. 
The formation of the scalariform fibre can be with ease 
traced. A large number of pitted oval cells, of considerable 
size, flow down as so many streams from the centre of the 
base of growth.' Some are seen with their end walls 
already absorbed, and their centre diameter contracting. 
A section of them made at this stage, shoAvs that the pits in 
their walls extend in lines around their whole internal struc- 
ture ; these now unite, so as to form furrows or folds. By 
looking into a tangental section of one of these cells, you may 
see in the interior an appearance as if the whole had been 
built up after the manner of a wall, for the divisions between 
each pit or depression are not quite obliterated. A small 
piece of such a cell, detached and flattened, has all the 
character of a fine hyaline network. Being anxious to dis- 
cover in what form one of these scalariform fibres became 
developed at its extreme point, I have made several prepa- 
rations of the vascular bundle, with the outer cell texture 
removed. By this means I have found that each of these 
processes push on in their growth exactly on the principle by 
which it commenced; they become periodically more con- 
tracted, and end in long, narrow, complete cells, with toothed 
edges, more similar to those of the fibres seen in the crys- 
talline lens of the eye of a fish, than to anything else with 
which I can compare them. 
I have one preparation, in which I have a beautiful specimen 
of this scalariform fibre, in close contact with true ribbon-like 
fibre disentangling itself, and perfect rings of the annular; 
this is from the plumule. None of these vascular tubes can 
1 succeed in colouring. I have no doubt but they are for- 
mations developed from elastic plasm, and by some law, 
assuming, according to their situation in the plant, their own 
peculiar character. It is easy to conceive that the folds of 
the scalariform could become annular; that the anniilar 
might be modified to become spiral; but I can form no 
conception as to the process, by which from an apparently 
homogeneous substance, the separation of two difibring sys- 
