. 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. CONSTRUCTION OP AN ORBWEB. 63 the wind directly from spiders' spinnerets, have observed the entanglement, have seen the animal draw the threads taut and then cross upon them. That all the lines are similarly formed and used I have no doubt. Mr. Terby, in a paper contributed in 1867 to the Royal Academy of Belgium, makes a number of intelligent and accurate observations upon the M Te b ^^^^* ^^ ^Pitlers to throw out their floati
. 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. CONSTRUCTION OP AN ORBWEB. 63 the wind directly from spiders' spinnerets, have observed the entanglement, have seen the animal draw the threads taut and then cross upon them. That all the lines are similarly formed and used I have no doubt. Mr. Terby, in a paper contributed in 1867 to the Royal Academy of Belgium, makes a number of intelligent and accurate observations upon the M Te b ^^^^* ^^ ^Pitlers to throw out their floating threads in order to "secure passage from point to point. lie demonstrated by numer- ous experiments that these threads could not be projected by the power of the spider without the aid of the wind. I regret that I only happened to fall upon this paper after the completion of my manu- script, so that I can insert here but a brief allusion to Black wall also had ob- served as much and gives a brief and accurate de- scription. The manner, he says, in which the lines of spiders are carried out from the spinners by a current of air appears to be this: as a preparatory measure, the spinnerets are brought into close contact and viscid matter is emitted from the spinning spools. They are then separated by a lateral motion, which extends the viscid matter into fine fil- aments, connecting the spools. On these filaments the current of air impinges, drawing them out from the Black- Fig. 61. A colony of spiders domiciled over water. spiimerets to a length which is regulated by the will of the animal, and on the spinnerets being again brought to- gether the filaments coalesce and form one compound line.^ It is a more difficult matter to determine whether the lines used for the foundations of orbwebs are formed in the same way. I have seen an orb- weaver, after traversing a considerable space by a series of successive bridge ' M. F. Terby, sur les proc^d^.s qu'emploient l
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectspiders, bookyear1889
