358 AMERICAN SPIDERS AND THEIR SPINNINGWORK. 
characteristic of Uloborus, Hyptiotes, and Dictyna are secreted by what he 
calls the Cribellum gland. The Lobate glands prepare the threads by 
which the insect is swathed previous to being eaten. Possibly, however, 
several glands take part in furnishing the swathing bands. The Pyriform 
glands secrete the spinningwork which forms the snare proper, or the 
seizing tissue, together with the dragline and trapline. I would venture to 
add to this the suggestion that the same glands must also secrete the fila- 
ments which form the ballooning thread and floating strands known as 
gossamer. The function of the Aciniform glands and Ampullate glands, 
according to Dr. Apstein, is not known. (See Figs. 348-354.) 
347 
Fic. 346. Spinning spool of Epeira diademata pyriform gland. X 188. Fic. 347. Longitudinal section of 
a spool of the aggregate gland. X 188. Fic. 348. Spinning spool of the glandula aciniformis. » 188. 
Fic. 349. Longitudinal section of a spool of the ampullate gland. 188. Fic. 850. Longitudinal sec- 
tion of spool of glandula tubuliformis. » 188, (After Apstein.) Fic. 351. An aciniform gland. xX 30. 
Fic. 352. A pyriform gland, » 105. Fig. 358. Longitudinal section of pyriform gland. 105. Fic. 
854. The spinning glands of Hpeira diademata in natural site. » 9. (After Apstein.) ac, aciniform 
glands; p, pyriform glands; am, ampullate glands; ag, aggregate glands; t, tubeformed or tubular 
glands (glandule tubuliformes.) 
Norr B.—Srcretion or Viscip Braps. 
Dr. Apstein is inclined to think that the foundation thread is created 
from the ‘ Aciniform gland.” As soon as the foundation is stretched the 
spools of the Glandule Aggregate (the Aggregate or 'Treeform Glands) are 
pressed on it, and leave on it a little drop of viscid secretion. ‘The three 
spools stand close together on the superior spinneret—that is to say, their 
mouths lay close together. If now the two superior spinnerets be pressed 
to the foundation thread, the six spools of the two sorts will embrace it, 
