11 - 
THE FLORIST’S JOURNAL. 
garded as mere accidental distensions ofltissue, by reason of the 
uniformity and beauty of their construction in the individual 
species in which they are found. In instances where their pre¬ 
sence seems to be indispensable to the life of the plant, they 
are internally uniform and smooth, whilst in others, where they 
do not appear to be essential, as grasses, umbelliferous plants, 
and some others, they are of irregular surface and figure, owing, 
probably, to the rapid growth of the stem, by means of which 
the tissue is rent asunder. 
Raphides are certain needle-shaped transparent bodies, ex¬ 
isting among the tissue ; they were first discovered in the milky 
juice of Euphorbia , and subsequently in other plants. If a 
common Hyacinth is wounded, a considerable discharge of fluid 
takes place, and in this fluid myriads of slender raphides are 
found floating. In some plants, instead of being of a circular 
form, they exist as minute conglomerated crystals. 
The general properties of the elementary organs of plants 
are, elasticity , extensibility , contractility , and permeability. The 
first gives to plants the power of bending to the breeze, and of 
vibrating without rupture ; the second enables them to develope 
with great rapidity whenever such is requisite ; the third enables 
any parts which may have been overstrained to recover their 
natural position when the disturbing cause is removed, and also 
causes the mouths of wounded vessels to close, and thereby 
prevent the loss of their contents ; the last secures the free 
communication of the fluid to every part of the vegetable struc¬ 
ture which has not become indurated by earthy depositions. 
The Cellular Tissue is the most important constituent of 
plants, as we may readily infer from its being the most abun¬ 
dantly and uniformly present, and also by its being the principal 
constituent of those compound organs, to which the preservation 
of the species is specially allotted. It may be regarded as the 
flesh of vegetable bodies, the substance which surrounds and 
keeps all the ramifications of the vascular system in their proper 
place : it is also the first which is generated in the case of 
wounds, or the developement of new parts ; thus, the granula-' 
tions at the base of a cutting or between the edges of two rings 
of the bark are cellular tissue. It transmits fluids in all direc¬ 
tions, notwithstanding that the sides of the cells possess no 
visible pores ; for in many plants no other tissue exists, and yet 
a circulation of sap goes on, and life is maintained. The medul- 
