THE PROCESS OF SPINNING 



341 



the bottom of which is situated the orifice of the spinning canal, 

 almost completely divided into two by the sharp edge of the rachis 



FIG. 331. Longitudinal section of the 

 spinneret : , horizontal portion of the tongue ; 

 b, vertical portion ; c,./', circle of the tongue ; 

 d, tongue-pad ; e, orifice of the spinneret ; g, 

 body of the lyre ; h, prebasilar membrane 

 forming a fold ; i, internal canal of the spin- 

 neret ; k, filator. After Blanc. 



Fie. 332. The lower lip (labium) of Bom- 

 Ityx mori, isolated, seen from the left side: 

 A, lyre; , spinneret; C, labial palpus; D, 

 vertical part of the labium ; E, horizontal part of 

 the same ; //, L, silk-canal ; K, right gland of 

 Filippi ; Z, canal of the left gland ; 3 T , labial 

 nerve ; a, oblique fibre of the elevator of the 

 labium ; ft, right fibre of the same ; c, depressor 

 of the labium ; d, superior spinning muscles. 



(Figs. 334, a, 335, /). The threads each pass into one of the two 

 grooves, and the layer of gum (grds) fills the rest of the canal of the 



press or filator. 



The silken substance is then pressed 



a >^ssS^S5g5>fev. ky ^g more or i ess powerful contrac- 



tions of the muscles of the filator, so 



FIG. 333. The labium in a hori- 

 zontal position, seen from the side : /, the 

 filator or press situated under the exter- 

 nal part of the spinneret (d), between 

 the branches (ft), of the lyre (a) ; e, labial 

 palp ; c, tongue. 



FIG 334. Longitudinal section of the spinneret and press (filator): A, filator or press; 

 B, spinneret; CD. body of the lyre; F, lower part of the labium ; E, common canal; eh, its epi- 

 thelium : <:, superior muscle of the press ; a, rachis ; 6, its posterior enlargement ; c, infundibulum ; 

 ft, cuticle; o, orifice of the spinning canal; op, central canal of the lyre and of the spinneret; 

 /?, hypodermis of the lyre ; ./', /, hypodermic pad of the lyre. 



