GLAND STRUCTURES. 



73 



bee-keepers are as much in the dark as those to 

 whom they look for leading. Leydig* and Sieboldt 

 did much to elucidate the structure of these glands, 

 but their methods of dissection were not sufficiently 

 refined to enable them to properly locate them in 

 the body of the bee ; Siebold, in particular, falling 

 into serious mistakes on more points than one, 

 followed by Girard, who does not appear to have 

 himself made any dissections. 



It has already been stated that the larva secretes 

 its cocoon from a gland, which reappears, in a 



Fig. 15.— Silk Gland of Bee Larva (Magnified Eighty times). 



A, Gland— p, Propria; el, Cell Layer; i, Intima ; r, Reservoir; sc, Secreting 

 (Jells. B, Transverse Section of Reservoir. C, Transverse Section of Secreting 

 Layer, with Interior Lumen, or Cavity. 



modified form, in the adult. This gland is seen 

 at Fig. 15. Its product, as is usual with insects, 

 remains perfectly liquid so long as it is stored in the 

 reservoir (r), but quickly hardens after it is drawn 

 out into threads, although not so rapidly but that the 

 several filaments where they cross each other partly 

 fuse together, and so much strengthen the gossamer 

 blind which the larva elaborates (see Fig. 4). The 

 secretion itself is derived from the blood by the 

 action of the cells (sc), seen in the cross section C, 



* " Archiv fur Anatomie Physiologie," &c, Ltipzig, 1859. 

 t " Mittheilungen iiber die Speichelorgane der Biene," 1872. 



