Page:Popular Science Monthly Volume 6.djvu/669

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THE TRIANGLE SPIDER.
649

contact with either of the radii. She then retraces her steps along the second radius to a point (6) nearly under that whence she started. The double line has shortened itself considerably; any slack she draws in, and then, turning about, with her head toward the apex, she makes a second attachment with her spinners close pressed against the radius.

Fig. 8. Net in Process of Formation.

The framework is completed, and the first interradial line (I') has been made. The subsequent movements of the spider are indicated by the figures 1 to 9. and by the interrupted lines and arrows. The dashed line 1. 2, 3, 4, shows the route which the spider followed in order to commence the second interradial. The dotted line 4, 5, represents her track while pulling out the first section of the interradial line; the dashed line 5, 6, shows her return to the proper point for attaching it. The dotted line 6, 7, and the dashed line 7, 8, in like manner indicate the track over which the spider passed in forming the second section of the second interradial. The dotted line 8, 9, shows the progress of the spider toward making the third section. The net is considerably reduced, but the spider is of about her usual size.

This Done, she again hangs from the radius, draws out the viscid line, and advances toward the apex, crosses at 7 to the third radius (R'"), retraces her steps thereon to 8, and makes a third attachment. She then repeats the same process upon the third radius, and, in Fig. 8, is represented as having finished about one-half of the line.

It must be borne in mind that the spider is not reduced, like the net; and also that, to save space, the interradial spaces are not so wide

    with a fine floss, as with the other Ciniflonidæ, but simply double lines, the two strands being from 1/500 to 1/2000 of an inch apart. My error exemplifies the utter insufficiency of property and function as a guide to structure, and enforces the general principle in natural history, that nothing should be stated as a fact that has not been verified by observation. It was his avoidance of this kind of error which rendered the work of the late Prof. Jeffries Wyman so remarkably trustworthy. Since the foregoing was in type, I have reamed from Mr. J. H. Emerton, of Salem, that some of his observations upon the structure and economy of this spider do not accord with those here recorded. It is to be hoped that the views of this accomplished and enthusiastic arachnologist will be incorporated with the new edition of Hentz's papers, which he is preparing for publication by the Boston Society of Natural History.