arachnidium

Century Dictionary and Cyclopedia

1. n. The characteristic organ of the Araneida, or true spiders; the glandular apparatus by which the silky threads forming cobweb are secreted and spun out. Numberless minute glands, provided with separate ducts, secrete the viscid material which hardens into silk when exposed to the air. The glands have been divided into five kinds: aciniform, ampullate, aggregate, tubuliform, and tuberous. Their ducts enter the arachnidial mammillæ, and discharge through orifices in the arachnidial papillæ.

GNU Webster's 1913

1. n. (Zoöl.) The glandular organ in which the material for the web of spiders is secreted.