Fig. 40.
This habit is not confined to any particular kinds of spiders, but is practised by many small species of Erigone, and by the young of many spiders of all families, that, when adult, would be too large for it. The majority of the spiders flying in autumn are the young of several species of Lycosa, that seem to spend the greater part of October and November trying to get as far above ground as possible. The best places to watch them are garden-fences in cities, where they often swarm, and can be more distinctly seen than on bushes. Large numbers can always be seen, for example, on the fences around the Common in Boston, every fine day in autumn, until there has been a long period of cold weather. Other species fly in the early part of summer.
Mr. Blackwall observed in Manchester, Eng., Oct. 1, 1826, a calm sunny day, that, just before noon, the fields and hedges were covered over with cobwebs. So thick were they, that, in crossing a small pasture, his feet were covered with them. They had evidently been made in a very short time, as early in the morning they were not conspicuous enough to attract his attention, and the day before could not have existed at all, as a high wind blew all day. At the same time large rags of web were floating about in the air, one measuring five feet long, and several inches wide. These appeared to be not formed in the air, but torn from grass and bushes, where they were produced by the tangling of many threads which had been spun separately. They kept rising all the forenoon, and in the afternoon came down again. Not one in twenty had a spider on it. Similar large webs were observed by Lincecum in Texas, and supposed by him to be balloons spun purposely by the spiders.
Mr. Darwin, in the journal of the voyage of “The Beagle,” says, that when anchored in the River Plata, sixty miles from shore, he has seen the rigging covered with cobwebs, and the air full of pieces of web floating about. The spiders, however, when they struck the ship, were always hanging from single threads, and never to the floating webs.
A recent account of the signs of weather-changes near the southern coast of the United States mentions as one of them cobwebs in the rigging.
It is still unexplained how the thread starts from the spinnerets. It has been often asserted that the spider fastens the thread by the end, and allows a loop to blow out in the wind; but, in most cases, this is certainly not done, only one thread being visible. Sometimes, while a thread is blown from the hinder spinnerets, another from the front spinnerets is kept fast to the ground, [Fig. 41]; so that, when the spider blows away, it draws out a thread behind it entirely independent of the one from which it hangs.
Fig. 41.