882 



TI-: XT-HOOK OF ENTOMOLOGY 



of Cossus, which are voluminous, were regarded by Lyonet as 

 <//.s.Wr//.s." Dr. Auzoux (1849), in his celebrated model 



Fio. 828. Left side of the head of the silkworm : ,i, adductor muscle of the mandible, from 

 which the muscular fibres have been removed; /', upper fibres of the same; <, lower fibres cut 

 away to show the adductor muscle (ct; </, tibres inserted on the accessory adductor lamella ; f\ 

 tMOphagUt, much swollen ; ff, salivary tf'.aml ; h, dorsal vessel ; /, I, trachere of the mamlibular niu's- 

 eles ; X% trachea; -, optic nerve. After Blanc. 



of the silkworm, represented them accurately, while Cornalia briefly 

 described them as opening into the mouth. The first satisfactory 



description is that of Blanc 

 (1891), who states that in the 

 silkworm "the two salivary 

 glands" are small, flexuous, 

 yellow tubes, which occupy a 

 variable position on the sides 

 of the oesophagus (Fig. 323). 

 The glandular portion passes 

 into the head, ending at the 

 level of the adductor plate of 

 the mandibles (Fig. 324, a), 

 and entering the bnccal cavity 

 at the base of the mandible, 

 as seen in Fig. 323. It is 

 plain, when we recognize the 

 direct homology of the silk- 

 glands of the caterpillars with 

 the salivary glands of other 

 insects, and of the spinneret 

 with the hypopharynx, that 



B 



Kiu. ;!-Jt. Lower side of the bead of the silkworm 

 exposed, the spiiininir apparatus, the o-sopliaireal iranir- 

 lion, and the adductor of the left mandible removed : 

 M. mandible; /', abductor of the mandible; A', ad- 

 ductor: .V, salivary irland attached at J to the edi.'e of 

 the adductor muscle; n, ,>, transverse portion of the 

 "hyniil"; :;. masticator nerve and its recurrent 

 branch (7) ; L, tongue cut horlzomtally. After Blanc. 



