the evening before or during early morning, each web being loaded with the fine particles of fog or dew. There had been very heavy rain on the 7th, so that the webs must have been spun out during the previous six or twelve hours from the time I noticed them—7·30 a.m. on the 8th. (It has never been properly explained by Darwin that by any process of reasoning a spider knew that it was safe to throw out its web, and that the day was going to be fine. I propose hereafter to read to members a paper bearing directly upon this subject, and being a continuation of the paper I had the honour of reading before members upon the Common Vital Force.)^*

The first thing that really struck my eye was the heavy shore-stay construction of one of these bridges, and I got down to examine it. It was a typical suspension bridge, quite taut, but the shore-stays much more extensive, heavy, and intricate than our engineers usually make. It had two long downstream steadying stays fastened to each bank; height above water, about 2ft. Drain itself, 4ft. to 5ft. wide, running through a fallen and burnt 5-chain track in the bush. The next bridge was a double bridge joined together by a centre span, but without so many shore-stays. The next one was also a double bridge, with strong upstream stays. The different parts of these double bridges appeared to support each other considerably.

The tautness of many of the bridges was peculiar, spiders' bridges being usually limber and free. Some of the double bridges were evidently accidental; but there could be no mistake in the tautening-up. No matter how the web crossed the stream, or crossed another web, the tautening-up when necessary put everything straight, and the structure itself in tension. The animal knew, I suppose, that in crossing water it would be necessary not to have too much play in the web, in order to avoid taking a plunge at times in the water itself, or the water rising to catch the slack.

No radiated-sail prey-web was hung upon any of these bridges. These were all suspended immediately on the side of the drain, or slightly overhanging the water, or upon the fallen burnt bush. There were vast numbers of these geometric webs, and very pretty they looked. I never remember seeing such a vast quantity, all of which must have been thrown out within the previous few hours. The animals perhaps were starving after a two to three days' rain. As the webs were spread out to the height of 8ft. from the ground upon any burnt limb, and as there were as many as ten or a dozen webs upon each limb, I thought at the time that it would be very difficult for any flying insect to escape being caught in one of

the webs. At the same time I could not help noticing that, numerous as the webs were, the little bush-birds flew in and out amongst them with unerring accuracy, never injuring one. The quickness and grace of the birds in avoiding the thousands of webs was most interesting to watch. I am particular in recording these circumstances and the exact date in order to allow future observers to watch the spiders work at this period of the year.

The downstream stays to the bridges (and nearly each bridge had two—one to each bank) were slack, and only served to steady the structures. The animals apparently threw these out as a matter of course, whether there was any wind or not. There was little or no wind that morning. We appear to dispense entirely with these shore-stays in our lofty flying bridges. But in the matter of the Victoria Bridge, lately washed away in the Brisbane floods, might not these shore-stays have been of great service? Of course, I do not for one moment wish to set my opinions against those of our great bridge engineers, seeing that I know very little of bridge-work; but I have always had great faith in nature's plan of construction. If we ever should use shore-stays like those to which I allude above, then I imagine such stays would have to be constantly inspected and renewed when worn at all. Two great cable-stays upstream might have saved the Victoria Bridge in Brisbane; but the engineer who constructed it can best say whether this was practicable or not. I only wish to point out that spiders apparently use such stays. The method of construction appeared to me to be as follows: The animal allowed so much web to float out of its spinnerets, and when it thought sufficient had gone to reach the opposite bank it tested the web, and if the web had caught on it took in the slack, and then attached the top-, bottom-, and side-stays, one by one, strengthening all and tautening all with cross-bars, the finished structure being an excellent suspension bridge. Most of the bridges were placed at an angle across the drain, showing how the web had floated out; but some were straight across.

The height of the shrubs forming the shore-pillars was about 1ft. to 18in. Along the edge of each side of the drain, and connecting pillar to pillar, were a multitude of side-webs (which I will call edge-webs), evidently for the purpose of further strengthening and tautening the bridges and pillars, and for quick locomotion. In its own mode of reasoning the little animal appeared to think that it could strengthen the shrub pillar by attaching shore-stays to its extreme tips, and side-stays also. I saw one bridge spring out from an edge-web, and then the edge-web strengthened and secured to the bank by a multitude of cross-bars. Amongst that myriad of