30 



A^fKIUCAN SPIDERS AND THEIR SPINNINGWORK. 



---sp.c 



sp.t 



Tlie si)inning field, SF, is an elliptical slope, which is situated on the 

 inner side of the s})inneret, and extends across the summit to the opposite 

 face of the tip. The basal part of the spinneret is cylindrical 

 Spiiinmg _^j^^| gradually grows smaller toward the spinning field. At the 

 lower or inferior edge is a row of long, strong branched bristles, 

 bb. On the inner surface, and at the border of the prolonged spinning 

 field, is a group of much shorter, stiff, simple bristles, sb. 



On each posterior spinning field is placed a number of spools, which 

 may be estimated roundly at one hundred and twenty. Besides these, there 

 are five larger spools, sp, wdiicli after Bucholz and Landois we may dis- 

 tinguish as spigots. Through these spigots issue a corresponding number 



of cylindrical and treeform glands presently to 

 be described. That part of the spinning field 

 which runs downward toward the base is com- 

 posed of numerous rows of long, closely placed 

 spools, l.ss. ; while that part of the field on the 

 summit is covered with short spools, s.ss. (See 

 Fig. 23.) Of the spinning spigots (Fig. 23), 

 four stand close together in one group towards 

 the middle of the spinning field, and one of 

 them is situated in the lower part of the field 

 (near l.ss.), and ap2)ears to be covered by the 

 long spinning spools. Of the four grouped 

 spigots, three give exit to treeform glands; and 

 the one farthest towards the base is connected 



F.G.24^ Middle spinneret, largely mag- ^^i^h a Cylindrical gland. The isolated S])00l 

 nined. sp.c, spigot discharging cylin- . 



dricai gland; ss, and s.ss, spinning sp, (near l.ss.) also discliarges a treefomi gland. 

 Tt^ritm gS.''"'"' '"■'' ''''°' The middle spinnerets are of a three faced 



pyramidal form. (Fig. 22, M, and Fig. 24.) 

 The leases are directed towards the front, while their points, lying closely 

 together, are turned immediately backward. They are unjointed.^ The 

 spinning field is triangular, and occupies almost the entire slope 

 S inner-^ ^^ *^^° si)inneret from base to point. It contains quite a number 

 ets. ^^ ^^^^^S spinning spools, which may be approximately estimated 



at one hundred- and fifty. On each middle spinneret there are 

 also three spinning spigots, of whicli two are close together at the tip, 

 sp.c, and give issue to cylindrical glands. A little further back, another 

 «pig«t gives exit to a treeform gland, si).t. Along the inner base 

 rior Spin- '^^^ ^^^^'^ ^^ bristles. The anterior spinnerets are of stouter pro- 

 nerets. l't)rtions and more conical shape than the posterior, from which 

 and the middle spinnerets they are divided by quite an inter- 

 vening space. (See Fig. 22, A, A.) Their inner bases are almost in contact 

 and are divided only by a tongue like chitinous leaf. Fig. 21, t. 

 ■ See Buf.liolz and Landois. Meckel describes tlieni as witli two joints. 



S.SS 



