Until maturity is reached the spider has the power to repair lost or damaged limbs.
When an insect strikes the web the spider loosens his hold of the trap-line, thus enveloping the victim in a tangle of threads which would otherwise not come into contact with it.
Compared to the spider web of highways in Los Angeles, it looked simple.
Take all the webbing of a normal spider, wad it up and tangle everything together then attach it to random points.
Westlake plugged forward, his nose nearly at the windshield, which was spider-webbed with nicks and cracks, as the old car crawled higher.
Beyond the introduction of the spider line it is unnecessary to mention the various steps by which the Gascoigne micrometer assumed the modern forms now in use, or to describe in detail the suggestions of Hooke, 4 Wren, Smeaton, Cassini, Bradley, Maskelyne, Herschel, Arago, Pearson, Bessel, Struve, Dawes, &c., or the successive productions of the great artists Ramsden, Troughton, Fraunhofer, Ertel, Simms, Cooke, Grubb, Clarke and Repsold.
Quekett in his Treatise on the Microscope ascribes to Ramsden the practical introduction of the spider web in micrometers.
There is no actual proof that this spider is more poisonous than others, but it is a significant fact that its species, inhabiting countries as widely separated as Chile, Madagascar, Australia, New Zealand and South Europe are held in great fear by the indigenous population, and many stories are current of serious or fatal results following their bites.
One interesting phenomenon in spider-life seems to be directly and certainly traceable to this influence, and that is mimicry of ants.
On the other hand it has been specially recorded of two of the species of spider-destroyers that they have great dislike and apparent fear of these little poisonous Hymenoptera.
This deviation is the adoption of an aquatic mode of life by the European fresh-water spider (Argyroneta) and by the marine spider Desis, which is found on the shores of the Indian and Pacific Oceans from Cape Colony to eastern Australia.
The nature of the integument and its hairy clothing in all spiders enables them to be plunged under water and withdrawn perfectly dry, and many species, even as large as the common English house-spider (Tegenaria), are so lightly built that they can run with speed over the surface of standing water, and this faculty has been perfected in genera like Pirata, Dolomedes and Triclaria, which are always found in the vicinity of lakes or on the edges of rivers and streams, readily taking to the water or running down the stems of water plants beneath its surface when pursued.
Apec vr7, a spider) to a class which he instituted for the reception of the spiders, scorpions and mites, previously classified by Linnaeus in the order Aptera of his great group Insecta.
If I were confined to a corner of a garret all my days, like a spider, the world would be just as large to me while I had my thoughts about me.
"I did what I had to in order to ensure the web never crashes down around the spider," he said.
Yet she'd seen the most incredibly huge spider dangling over her head when she awoke.
To obviate this difficulty Felice Fontana of Florence (Saggio del real gabinetto di fisica e di storia naturale, 1 755) first proposed the use of spider webs in micrometers,' but it was not till the attention of Troughton had been directed to the subject by Rittenhouse that the idea was carried into practice.'
But experience soon proved the superiority of the spider web; its perfection of shape, its lightness and elasticity, have led to its universal adoption.
To avoid such error Dawes used double wires, not spider webs, placing the image of the star symmetrically between these wires, as in fig.
Da and The micrometer box, and of course with it the whole system of spider webs, is moved by the screw s, whilst the measuring web is independently moved by the screw S.
Repsolds' more recent form of the spider-line micrometer (since 1 The marks of varnish so applied will he seen in fig.
Instruments have been invented by Alvan Clark and Sir Howard Grubb for measuring with the spider-line micrometer angles which are larger than the field of view of the eyepiece.
Reseau-square by means of a spider-line micrometer, a glass scale, on the plan shown in fig.
The microscope or viewing telescope is fitted with a spider-line micrometer having two screws at right angles to each other, by means of which readings can be made first on one reseau-line, then on the star, and finally on the opposite reseau-line in both co-ordinates.
By employing both hands, operation (I) can be made as quickly as a single pointing with the ordinary spider-line micrometer, and operations (2) and (3) can be similarly performed in the time required for a single pointing.
17, § 12) mentions its immunity from wolves and poisonous snakes - which it still enjoys, - but Solinus (l.c.) mentions a poisonous spider, called solifuga, peculiar to the island.
White or grey spots may be due to Peronospora, Erysiphe, Cystopus, Entyloma and other Fungi, the mycelium of which will be detected in the discoloured area; or they may be scale insects, or the results of punctures by Red-spider, &c. Yellow spots, and especially bright orange spots, commonly indicate Rust Fungi or other Uredineae; but Phyllosticta, Exoascus, Clasterosporium, Synchytrium, &c., also induce similar symptoms. Certain Aphides, Red-spider, Phylloxera and other insects also betray their presence by such spots.
Besides these, or part of them, certain copies contain sections of unknown origin about the bee, the stork, the tiger, the woodpecker, the spider and the wild boar.
The order is well represented in Britain by 18 genera, which include several species of Orchis: Gymnadenia (fragrant orchis), Habenaria (butterfly and frog orchis), Aceras (man orchis), Hermin- ium (musk orchis), Ophrys (bee, spider and fly orchis), Epipactis (Helleborine), Cephalanthera, Neottia (bird's-nest orchis), one of the few saprophytic genera, which have no green leaves, but derive their nourishment from decaying organic matter in the soil, Listens (Tway blade), Spiranthes (lady's tresses), Malaxis (bog-orchis), Liparis (fen-orchis), Corallorhiza (coral root), also a saprophyte, and Cypripedium (lady's slipper), represented by a single species now very rare in limestone districts in the north of England.
If an aperture for ingress and egress, for purposes of feeding, were left in the wall of such a chamber, there would arise in a rudimentary form what is known as the tubular nest or web; and the next important step was possibly the adoption of such a nest as a permanent abode for the spider., Some spiders, like the Drassidae and Salticidae, have not advanced beyond this stage in architectural industry; but next to the cocoon this simple tubular retreat - whether spun in a crevice or burrow or simply attached to the lower side of a stone - is the most constant feature to be observed in the spinning habits of spiders.
Its upper side is always covered by the spider with pieces of the vegetation growing hard by, so that, when the door is closed, the position of the burrow is completely concealed.
Mosquitoes are rarely troublesome; gadflies, and a large spider (hangeyu), which spins a web resembling golden silk, are common, as are scorpions and centipeces.
Be that as it may, the snare in many instances, as in that of the Agalenidae (Tegenaria, Agalena), a family closely allied to the Lycosidae, is a horizontal sheet of webbing, upon which the spider runs, continuous with the lower half of the aperture of the tube, of which it is simply an extension.
A very similar sheet is spun by a species of Linyphia, one of the Argyopidae, but in this case there is no tube connected with the web and the spider hangs suspended beneath the horizontal netting.
Passing back from the centre of the web to the underside of an adjoining leaf or some other sheltered spot runs a single thread, the trap line affording passage to the spider to and from the sheltered spot and the snare itself.
No sooner is the vibration perceived than the spider descends with all speed to the centre, and by feeling the ends of the radiating lines learns which is ashake and rapidly, without the possibility of mistake, makes its way to the entangled insect.
Perfect orbicular webs are made by many genera of Argyopidae (Zilla, Meta, Gasteracantha), the best-known example being that of the common garden spider of England, Aranea or Epeira diademata; but these webs are not associated with any tubular retreat except such as are made under an adjoining leaf or in some nook hard by.
It was formerly supposed that this custom was peculiar to a single species, which was called the "gossamer" spider from the fact that the floating webs, when brought to the earth by rain or intercepted by bushes and trees, coat the foliage or grass with a sheeting of gossamer-like silk; but the habit is now known to be practised by the newly-hatched young of a great variety of species belonging to several distinct families.
As a commercial product spider-silk has been found to be equal, if not superior, to the best silk spun by lepidopterous larvae; but the cannibalistic propensities of spiders, making it impossible to keep more than one in a single receptacle, coupled with the difficulty of getting them to spin freely in a confined space, have hitherto prevented the silk being used on any extensive scale for textile fabrics.
If in the latter case the spider be afraid to come to close quarters, various devices for securing it are resorted to.
One genus of Thomisidae (Phognarachne), which inhabits the Oriental region, adopts the clever device of spinning on the surface of a leaf a sheet of web resembling the fluid portions of a splash of bird's dung, the more solid central portions being represented by the spider itself, which waits in the middle of the patch to seize the butterflies or other insects that habitually feed on birds' excrement and are attracted to the patch mistaking it for their natural food.
Except in the case of the water-spider (Argyroneta) the males are smaller, sometimes very much smaller, than the females, but have proportionately longer legs and smaller bodies.