"There Came A Big Spider . . ."

Auckland Star, Volume LXX, Issue 219, 16 September 1939, Page 7 (Supplement)

"There Came A Big Spider . . ."

(Part I.) DHOBABLY in the lines of the nursery rhyme about Little Miss Mutfet most of 11s were first introduced to spiders. Our impression then, from the words: l'here came a big spider, \\ hicli sat down beside her, And frightened Miss Muffet away, would lie that spiders were rather terrible creatures. Whether or not my feelings towards this great family of living things were influenced by such an impression, I cannot say; but I do know that whereas a spider causes me to shudder there are others who quite like handling them, and can even carry them about in their hands without experiencing any unpleasantness. That, however, is something I cannot do, but all the i-ame 1 <1 o realise that like all other groups of living things the spider is well worth a little studv.

Kven a brief article like this should enable us to learn quite a lot about these treasures. I nearly wrote

"about inseetp," but that would not l>e correct, for a spicier is not really an insect. That may be the class into which we frequently put it, but as a true insect has six legs, no more and 110 less, the spider cannot be clawed a* such, for just as constantly as the insect possesses three pairs of legs, so the spider boasts four pairs of true walking and two other pairs of limbs.

The lirst of these two oth«r pairs are known as the falces or falcers, which are really poisonous fangs, lliese are a form of mandibles, by means of which injection of poison is made into the wound they inflict on victims. The claw joints of the falces are also put to the use of extracting the juices and soft parts of the same victims.

The second pair of limbs are termed the "pedipalps." Those may also be described as tlie second pair of mouth organs (not tlie musical kind!)- —the falces being the first. In some cases tlie pedipalps are leglike and in others they terminate in a claw. In adult male spiders these limbs are highly modified as depositors of the fluid which assists in the process of reproduction.

Behind the pedipalpe we find the four pairs of true walking legs, already referred to, each leg having seven joints (the falces are twojointed, and the pedipalps sixjointed). Although we cannot 6ee with the naked eye—at least not from the distance I like to keep from spiders!—yet we are told on giod authority that each leg terminates in two or three curved claws, these claws in turn bein<j usually armed with cr>mb teeth. Some e-pecies have an additional fixture on their

legs and that is a series of close bristles ori the joint before the last, these bristles being used to tease out a special tyi>e of silk produced by tlie extra "spinner" with which they are provided. When so teased, this silk becomes particularly fluffy and sticky, and is then put to good use by the spider, which spreads it on the snare or web.

So much for the legs and other limbs. Now, what about the eyes. Yes, tlicy are worthy of special mention, even if only by virtue of their numliers, for most spiders possess 110 fewer than eight of these members. Some, it is true, can boast only six, but even that number is nothing to be ashamed of. The positions of these eyes vary considerably, as does also their sizes, and this is of considerable importance in the classification of the various members of the family. With an insect, the various segments of the body are the head, the thorax and the abdomen, and while they are the same in one way with the spider, yet there is a difference in that the head is not separated from the thorax by a neck. Thus, although having a head, the spider's body is really divisible into two parts only. The upper part is, therefore, termed the cephalo-thorax, the first part of the word being derived from the Greek and meaning "connected with the head." Thus we may describe the anterior part of the

spider merely as the "thorax con-nected-with-the-liead," and separating this portion from the posterior or rear part —the abdomen —is a welldefined waistline.

So far 110 mention has been made of a characteristic of the spider family (the Arachind family, as we may as well term them if we would be precise) —and that is the possession of a cluster of spinners or spinnerets. These may well be termed their most striking characteristic, for it is from them that the silk of the web issues. Six or eight is the usual number of spinners to be found on a spider and these are situated near the a[>ex of the abdomen. The fluid secreted from these glands is viscid, hardening 011 exposure to the air, and thus forming the thread with which we are all familiar.

The use to which we see the thread put most frequently is that of forming the web—a snare in which the spider entraps insects, upon the juices and soft parts of which it subsists. Anyone who has observed even casually will know how diverse are the forms of webs to be found even in our daily round. How much more varied they must be among the thousands of species of spiders we do not encounter.

Probably the most familiar type of web is the beautiful wheel-shaped structure, which shows off to such advantage when begemmed with dewdrops early in the morning.

There are other types, however. Some are merely masses of tangled thread, some are horizontal snares while others again are tubular structures fixed ill the jrround from the recesses of which the spinner receives his victim.

By Olga P Burton

The silken thread has other use* as well, for we find that the cocoon for the eggs of the spider is made of silk; a thread of the same material often saves a spider from falling, and anyone who has watched a spider dangling on the end of thk gossamer lifeline, running it out or "rolling" it up apparently at will, will have some idea of the strength of the thread, and of the use it is to the spider in this way.

'Die wheel-shaped web is an intricate structure and the marvel of it that from the body of quite a small creature comes all the material ag required, while the solitary spinner fashions the web in all its delicate intricacies in a perfect manner. Firstly, a horizontal cord is fixed between two firm points—and that in iteelf is no mean task for a creature without wings.

Surely the spider deserves the reputation of "try, try and try again,* as given to it by King Robert the Bruce, for if we remember that in the laying of this initial thread there may be entailed an enormous amount of travelling up and down, the haul, ing in of much slack thread, and the expenditure of much ingenuity and patience, we see that even the beginning of the web is quite a task in itself. And yet we brush away * spider's web so easily and with n* thought for all the labour expended. And then, of course (unless we get the spider with the web), it will just set to work to build it up again—and again, if necessary.

Sometimes the initial threads may be fixed by the spider sending out a length of silken cord which is wafted by the breeze until it attaches to a firm point.

The framework then proceeds, stays and connecting lines being put in place. Spokes and spiral connecting lines then follow, until the beautiful and marvellous structure is complete, the centre often being cut away and filled again with an irregular mesh of non-adhesive thread, upon which the spider reclines. The thread of the spiral lines is finer than that of which the spokes are composed, and is much stickier. When at rest in the centre of the web the spider will keep each leg in contact with a spoke, and is thereby able to detect the portion of the web from which comes any vibration from an ensnared insect.