INSECT ENGINEERS. THE WONDERS OF SPIDERS' WEBS.

Progress, Volume I, Issue 8, 1 June 1906, Page 205

INSECT ENGINEERS. THE WONDERS OF SPIDERS' WEBS.

The spider s web which is brushed from our walls with such ruthlessness by the tidy housemaid, is a remarkable example of the ingenuity displayed by these tmy insects, and thoroughly entitles them to be regarded as expert engineers. The web is m reality a huge network of cables, the construction of which demands what appears to be a considerable amount of thought. Mr. Maurice Koechlin describes this intricate process in La Nature • — " A great principle never forgotten by the spider is that she must always spin behind her a thread that will enable her to find again the points that she has left ; this serves at once as her guiding thread for return, and as the road on which she travels. A consequence of this rule is that the starting-point, the centre of the first operation, must be at the top of the web, and often higher still, so as to dominate the whole." " From this point the explorer lets herself down, suspended from her inseparable thread, balances herself, and if she does not find the sought-for point climbs back along the thread, which she absorbs m ascending. There are, necessarily, experiments at first, some useless threads, and others that serve as false work, but never is an auxiliary cable left in the unfinished web." " The spider carefully tests each thread, renewing and repairing where necessary. The threads which stand the greatest strain are larger than the others, and no break is ever seen m them. A net as a rule lasts only for a day, as the threads quickly lose their strength and elasticity. It is replaced every morning, except when the spider has either a day's provisions in advance or when she is old and sluggish. As the spider grows, so the size of the web is increased." There seems to be a distinct process of thought m many of the spider's 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 m place, the worker returns to the centre, and touches the threads one by one, as if counting them, but really she is seeing whether one may not be wanting ; and when she finds that, by mistake, too great a space has been left anj^where, she fills it with a supplementary thread. . . . When by reason of the obliquity of the framework the radii become too long, the spider makes a new transverse line of attachment. " The last part of the work, the long spiral, demands patience, for it turns about the centre of the web a great number of times, and each spiral must be fastened to all the radii. The latter, owing to their elasticity, are very mobile and they must therefore be held in place. As a seamstress, when putting together two pieces of cloth, begins by basting them at the principal points of contact, 50 the spider makes a provisional spiral with large turns, which aids her in putting m the permanent spiral, and which is removed later."

Good cheer is half of good courage