No. 489] 



SILK (,!.AM}S OF A l'A\T/-f.l-:s 



573 



Berlese, '06, denies the pres(>n(e of a press in the silk glands of 

 the larvae of Hymenoptera, Diinera, and ( "oleoplera. He figures 

 a sagittal section of the head of the lai-\a of X iilotoma rosae hut 

 does not represent muscles as j)n'sciit in the ri^uion of the con- 

 ducting tuhe. On the other lunid the pn>>cnre of a press in liviiicn- 

 opterous larvae has heen recordc<l l.y l-ckst.Mn, 'HO, in Ij/da 

 pratcnsi,, and IMkel, in Loplnirus ph,l. 15., d. of workers 

 figure this oruan as preset hut uixc no defn.ite <l(lails n-anlinu 

 its structure. Tikcl states that in structure it is siuiihu- to that 

 descrihed hy Tichornirow for Bntulnix wnri. 



Sfrurfmr'offin /'/v..s.- In the (asr of Apanhh. nhmuraiu.s the 

 press is highly developed, it couuneuces at the union of (he two 



than half'of die conunon duct. Dorsally the press is' <.otu'ave. 

 traxersrd hy a lono-im.hiud fuirou into ^^\^n■\^ pass dorsal pair 



fi-s. 1'7, J!»an(l;!(). The Neutral surface is ( on\.-\ , Fius. JTand.'^O); 

 its ((>IIs are son.cuhat elonualed and s(-< ,vtc the thicker <-hitinous 

 layer of tlu^ conunon .hict. The dorsal uium h-s consist ot nuuicr- 



of M-N e.al (ihcts. Thc^ are l.u aled as sh<,v n in c ross tion in Fi.. 

 27. 'V\w^ are insrrte.i on opposite si<les of the press and. passing 

 almost direcllv veutrad. have their origin on the veiUral ho.ly wall, 

 being attached <lirectly to the chitiu. . 



'i"he huuen of the press, as seen in ( ross se( tion i Tiu. 27 is hoise- 

 shoe-like in form. When the uuiscies are n>ia\ed this lumen is pM< - 

 ticalh <'losed, thus prcNcntinu- the furthei (-ress nf the thiead. The 



dexelope.! on the \entral si.Ie. This 'ehiliuocs kn.M' is dire, th 

 continuous u i,h that of the <lucts lu Fi.. 27 the dorsal poniou of 

 this iaver appeals thi<k.l.ut this is due to theol.li.inu> of ihesMti.Mi 



