The means by which female wolf spiders attach an egg sac to their spinnerets was investigated using scanning electron microscopy. In four Pardosa species, we observed that silk fibers emerging from ampullate gland spigots had been affixed to the surface of the egg sac. More specifically, primary (1Њ) and secondary (2Њ) major ampullate (MaA) glands and 1Њ and 2Њ minor ampullate (MiA) glands all contributed fibers for this purpose. The diameters of the 2Њ MaA and 2Њ MiA fibers were greater than

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... ose of the 1Њ MaA and 1Њ MiA fibers and, correspondingly, the widths of the 2Њ ampullate spigots were clearly greater than those of the 1Њ ampullate spigots. Larger 2Њ ampullate spigots were also observed in adult females of species from three other lycosid genera. Thus, 2Њ ampullate glands, which in araneoids function only in juveniles during proecdysis, are not only functional in adult female lycosids (and adult females of several other families), but they appear to play a greater role than the 1Њ ampullate glands in egg sac attachment. Observations made on the 1Њ and 2Њ ampullate spigots of adult females from species belonging to several other families are also presented. Cuticular structures referred to as nubbins and tartipores are present in some spinning fields on spinnerets. A proposal is made for defining these terms by a criterion, namely their different origins, which differs from that applied previously.