. Manuale di natura-studio per insegnanti e genitori, basato sulla natura di Cornell-studio di volantini. Lo studio della natura. 484 Handbook of Nature-Study. La mongolfiera ragni di insegnante di storia F guardiamo tutta l'erba alcuni caldo e soleggiato mattino- ing o serata di inizio di caduta, possiamo vedere fili di seta di ragno aggrappati ovunque; questi non sono nastri regolari per intrappolare insetti, ma sono a singolo thread filate dalla levetta di erba alla levetta di erba fino a quando i campi sono tappezzate con scintillanti di seta. Abbiamo una fotografia di un campo arato, adottate in autunno, che guarda ama le onde del lago; così completamente è il suolo coperto w

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. Handbook of nature-study for teachers and parents, based on the Cornell nature-study leaflets. Nature study. 484 Handbook of Nature-Study. BALLOONING SPIDERS Teacher's Story F we look across the grass some warm sunny morn- ing or evening of early fall, we see threads of spider silk clinging everywhere; these are not regular webs for trapping insects, but are single threads spun from grass stalk to grass stalk until the fields are carpeted with glistening silk. We have a photograph of a plowed field, taken in autumn, which looks likes the waves of a lake; so completely is the ground covered with spider threads that it shows the "path of the sun" like water. When we see so many of these random threads, it is a sign that the young spiders have started on their travels, and it is not difficult then to find one in the act. The spiderling climbs up some tall object, like a twig or a blade of grass, and sends out its thread of silk upon the air. If the thread becomes entangled, the spiderling sometimes walks off on it, using it as a bridge, or sometimes it begins again. If the thread does not become entangled with any object, there is soon enough given off, so that the friction of the air current upon it supports the weight of the body of the little creature, which promptly lets go its hold of earth as soon as it feels safely buoyed up, and off it floats to lands unknown. Spiders thus sailing through the air have been discovered in mid-ocean. Thus we see that the spiders have the same way of distributing their species over the globe, as have the thistles and dandelions. It has been asked what the spiders live upon while they are making these long jour- neys, especially those that have drifted out to sea. The spider has very convenient habits of eating. When it finds plenty of food it eats a great deal; but in time of famine it lives on, apparently comfortably, without eating. One of our captive spiders was mislaid for six months and when we found her she was as

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