TIPULA. 
it so happen that the germ of the mischief has 
been closed up along with it. Exposure to a 
considerable degree of dry heat, wherever that is 
practicable, is the easiest and most effectual 
mode of destroying the eggs and larve. Im- 
mersion in boiling water is, of course, equally 
effectual. The objects preserved in museums 
are protected from moths, as well as other de- 
structive insects, in various ways. Corrosive 
sublimate, dissolved in spirits of wine, has been 
a good deal used of late, and is said to be very 
efficacious. Spirits of turpentine, oil of petro- 
leum and camphor, although, perhaps, they do 
not actually kill the noxious insects, are yet 
very useful in driving them away. A preparation 
which speedily kills them, and which is said to 
be the best possible preservative, is that called 
Becceur’s soap, which consists of the following 
ingredients in the proportions indicated :—2 lbs. 
of arsenic in powder, 2 lbs. of white soap, 12 oz. 
of salt of tartar, and 4 oz. of lime in powder. 
Sulphurous fumigations have long been used with 
advantage, but must be employed with caution, 
as they are apt to injure the colour of certain 
objects.” 
TIPULA. A genus of dipterous insects, be- 
longing to the nemocera family, and constituting 
the type of a group called Tipulariz. The species 
of this group are very numerous, and have singu- 
larly long legs and narrow elongated bodies, and 
are popularly known by many quaint names such 
as crane-flies, long-legs, tailors, and Jenny-the- 
spinners. Their antenne have thirteen joints,— 
the radical one of which is cylindrical, the second 
cup-shaped, and the rest cylindrical and bearing 
each at the base a few verticillate hairs; the 
palpi are projecting, incurved, cylindrical, and 
four-jointed, and have the terminal joint elongat- 
ed; the ocelli are a-wanting ; and the wings are 
lanceolate and spreading. The larve and pupz 
of some inhabit the water and form vegetable 
galls; and the larve of others live within the 
soil of meadows and arable land, and frequently 
make great devastation by loosening and destroy- 
ing the roots of herbage plants and gramineous 
crops. Not fewer than at least forty species 
occur in Britain; and several of them are very 
common, and often work great havoc. Two of 
the worst—the one a true tipula, and the other 
a species of the genus cecidomyia—are noticed in 
the articles Grup and Wuerat-F1iy; and these 
Serve as a sufficiently ample specimen of the 
whole group. 
TISSUE, in Borany. All the organs and parts 
of plants are composed of little cells or vesicles, 
tubes, and fibres; or, in other words, of cellular, 
vascular, and woody tissue. The first is of uni- 
versal occurrence; but the latter are partially 
or entirely wanting in many plants. 
Cellular tissue consists of membranous vesicles, 
or little bladders, which cohere with each other, 
more or less perfectly, by their contiguous sides. 
These are not perforated with holes or visible 
| see URE A 
TISSUE. 
pores, at least originally: they are at first of ex- 
treme tenuity ; but are often thickened by the 
deposition of more solid matter upon their inner 
surface, either in regular layers, in bands, dots, 
or otherwise, and which sometimes accumulates 
so as completely to fill the cell. Their form de- 
pends entirely upon the circumstances in which 
they are placed. When separate they are round 
or oblong: when equally pressed together, they 
become twelve-sided, the cross-section being six- 
sided: when stretched lengthwise, they are ren- 
dered prismatical, cylindrical, &c. They contain 
fluid, and often solid matter, such as starch, the 
green colouring substance of plants, and some- 
times minute crystals, which, when slender, are 
termed raphides. Common cellular tissue, or 
parenchyma, constitutes all the pulpy and succu- 
lent parts of plants, the pith, the whole of leaves, 
excepting the veins, and a portion of the bark, 
&c. But it is capable of acquiring excessive 
hardness; as it does in the stone of a peach, 
and in the bony skin of some seeds. One or 
more fine spiral lines are sometimes observed on 
the walls of a cell; forming what is called fibro- 
cellular tissue. See the article CunivLar Tissus. 
Woody tissue consists of vesicles of cellular 
tissue drawn out into tubes of extreme tenuity 
and toughness, their sides being very thick in 
proportion, each end tapering into a sharp point. 
These fibres are closely applied to each other by 
their sides, and form bundles or coarser fibres 
stretching through the plant lengthwise, afford- 
ing the necessary degree of strength, and also 
serving, it is supposed, for the upward convey- 
ance of the sap. This tissue is not confined to” 
the wood, but is also found in the bark; and the 
veins of leaves, of petals, &c., are chiefly com- 
posed of it. In all coniferous trees (pines, firs, 
&c.), and in a few others with aromatic secre- 
tions, the tubes of woody tissue (which are larger 
than ordinary woody fibre) are marked along 
their sides with circular gland-like disks, ap- 
pearing like a row of small holes. 
Pitted, or vasiform tissue, consists of large 
tubes, either composed of ordinary cylindrical 
cells placed end to end and opening into each 
other, or often without the appearance of such 
composition: the walls are marked with pits or 
dots, produced by the unequal deposition of more 
solid matter on the inside. They were long con- 
sidered as true vessels, and have been called dot- 
ted ducts. The pores conspicuous on the cross 
section of most kinds of wood, are the large open 
orifices of these tubes. 
Vascular tissue consists of uninterrupted mem- 
branous tubes, marked with transverse bars or 
rings, or with a spiral fibre adherent to their 
inside. The type of vascular tissue is the spiral 
vessel ; in which the closely coiled spiral fibre is 
capable of unrolling with elasticity. The thin 
and delicate membrane which confines the fibre 
being transparent, the latter only is visible, and 
resembles a slender coil of fine wire. In their 
, 
ELE - a a 
