. American spiders and their spinning work. A natural history of the orbweaving spiders of the United States, with special regard to their industry and habits. Spiders. THE SENSES AND THEIK ORGANS. 293 the movement was not so decided. At night the direction was reversed, and the migration set toward the library lights, and the colony settled as near them as j)ossible. This behavior was so often and uniformly observed that the conclu- sion was quite satisfactory, but I nevertheless ma4e a series of experi- ments which fully confirmed it. For example, one evening I found the brood massed at two
. American spiders and their spinning work. A natural history of the orbweaving spiders of the United States, with special regard to their industry and habits. Spiders. THE SENSES AND THEIK ORGANS. 293 the movement was not so decided. At night the direction was reversed, and the migration set toward the library lights, and the colony settled as near them as j)ossible. This behavior was so often and uniformly observed that the conclu- sion was quite satisfactory, but I nevertheless ma4e a series of experi- ments which fully confirmed it. For example, one evening I found the brood massed at two points (a and b, Fig. 287) on either side of a toy wooden column, hanging in a dim light which fell from a lamp that previously had been turned down. An oil lamp giving a bright light was now lit, and so placed (beyond the point c) that one cluster (at a) was in shadow, the other (at b) faintly illuminated. In twenty minutes twelve individuals had passed over from the partly shaded spot (b) to the illuminated point (c), and about half the group in the shadow (at a). FKi. 287. Experiment to show the perception of light by young spiders. The group in shade were all transferred to the shelf by lighting the lamp thereon. had crossed to the better light at b. The lamp was then removed to the opposite side of the table, reversing the conditions of light, casting c in the shadow, b partly in the shade, and throwing full light upon a. Instantly a movement began among the spiders now in the dark at c, who turned and ran rajjidly along the lines communicating with the col- umn. In less than two minutes only four of the twelve remained; one of these soon followed, and shortly the other three. In the meanwhile the shaded group at b was being broken up by an active transfer to the illu- minated section at a. Another experiment gave the following results: I cajjtureil a female Epeira sclopetaria at Atlantic City and placed her within a box to cocoon. May 2()th, a cocoon was formed in the ang
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectspiders, bookyear1889
