INSECT ENGINEERS.

Poverty Bay Herald, Volume XXXIII, Issue 10574, 27 January 1906, Page 1 (Supplement)

INSECT ENGINEERS.

0:0— — THE WONDERS OP SPIDERS' WEBS.

The spider's woo which is brushed from our* wujis with such iutniet.M_t.s_- uy nits tidy iiouewinaid, is a remarkable example oi tne ingenuity displayed by these tniy insects, and thorouguly entitles them to regarded as expert engineers. The web js m reality a huge network of cables, tue conduction of wuicu demands what appears to be a considerable •amomit* ol thougut. Mr Maurice Jvoechlin describes thia intricate process m La Nature s—

"A great .principle never forgotten by the spiuei- is tnat she ihust always epm behind her a thread that Will enable ncr to nnd tne points tnat sue nas leit; tliis serves at once as her guiding thread lor return, and as the roao on wnich sue traveis. A consequence of this rule "is that the starting-point, the centre of the hist operations, must be at the top ol the woo, anu olten higher stiu, so us w dominate the whole. "

"From tnis point, the oxplorer lets hersell uown, suspended irom ncr lnsepai-aoie inroad, balances hei-seii, anu 11 sue does not nud the sought-for point, climb 8 bact aiong tlie thread, which sue absorbs Hi ascending, xhere are necessarily expeiv ,meut« at first, some useless threads, and others that serve as iaise work, hut never is an auxiliaiy cable left m me finished web."

The spider, carefully ttats each thread, renewing und repairing wnere necessary. The tlueads wuleh stand the greatest strain are larger than the others, aud no break is ever seen m them. A net as a rule lasts only for a day, as the threads quickly lose tneir strength and elasticity. It is replaced every mpniuig, except when the spider has either a day's provisions m advance or when she is old and sluggish. As the spider gjows so tlie size of the web is increased.

There seems to be a distinct process of thought m many of tho spiders actions. The first thing done is m the construction of the framework ; then the radii are fixed from side to side :

"When all the radii are iv place, the worker rcTunis to the centre, and touches the threads one by one, as if counting them, but really 6he is seeing whether one may not be wanting; and when she finds that, by mistake, too great a space has been left anywhere, she fills it with a. supplementary thread. . . .' When, by reason of the obliquity of tlie framework the radii become too long the spider makes a new transverse line of attachment.

"The last part of lhe work, the long spiral, demands patience, for it turns about the centre of the web a great number of times, and each spire must be fastened to all the radii. The latter, owing to their elasticity, are very mobile and they must therefore be held iv placo. As a seamstress, when putting together two piece s of cloth, begins by basting them at the principal points -of contact, so the spider makes a provisional spiral with large turns, which aids her m putting m the permanent spiral and wliich ia removed later."