ON THE ANATOMY OF THE ARANEIDEA. 163 
in the still air of a room, without any influence of the wind, to the objects 
towards which they were directed *. 
Spiders are exceedingly sagacious, and vary the expedients which they 
adopt to escape from confinement or to reach a neighbouring object. I was 
much interested lately in observing one (Hpéira inelinata) shift its position. 
It was on a horizontal piece of wood, and wished to reach another piece 
placed about a foot beneath it, and at a short distance from it laterally. It 
suddenly dropped, spinning a thread as it fell, which of course it had first 
fixed to the wood above. When it had fallen to a little below the level of 
the object which it wished to reach, it stopped itself by catching the line with 
one of its feet, and remained suspended in the air by the thread. It now 
made several violent jerking movements, and thus acquired a swinging mo- 
tion, which it managed to increase until it brought itself into contact with 
the neighbouring object: as soon as this was effected, it clambered on to it, 
and walked leisurely away. 
EXPLANATION OF THE PLATES. 
Pirate XVI. 
Fig. 1. Portion of the muscular layer of integument. 
Fig. 2. Spinnerets from a large species of Olios. 
Fig. 38. Spinnerets of Hpéira diadema, with motor muscles. 
Fig. 4. Portion of one of the same muscles, greatly magnified, showing its 
attachment to the skin. 
5. Spinnerets of Ciniflo ferox:—a. Extra spinnerets, which form the 
flocculus; 5. Cribriform surface on the same. 
6. a. Papille or spinning tubes on a portion of a spinneret; 6. Highly 
magnified view of one papilla. 
Fig. 7. Striated muscle from the interior of abdomen :—a. Bundle of fibres ; 
b. One fibre, highly magnified. | 
Fig. 8. Fat lobules. 
Fig. 9. Interior of the abdomen of Epéira diadema, showing the silk-glands 
in situ. 
Fig. 10. One of the spinnerets of Epéira diadema, with portions of striated 
muscle, and some of the small oval and fusiform glands attached. 
Fig. 11. Two of the fusiform glands, with their granular capsules highly 
magnified. 
Fig. 12. a. Oval gland, from Epéira diadema, showing its embossed appear- 
ance ; 6, Ditto, from a large species of Mygale, showing its duct 
with a fibrous covering. 
Fig. 13. Minute glands near the supplementary spinners in Ciniflo atroa; 
two ordinary glands appear with them. 
Prats XVII. 
Fig. 1. Cartilaginous or hard silk-glands:—a and 6. Two varieties from 
Epéira diadema; ce. Variety from Agelena labyrinthica. 
Fig. 2. Membranous sac and duct from Agelena labyrinthica. 
Fig. 3. A portion of the body of the same, highly magnified. 
Fig. 4. A portion of the duct of the same, highly magnified. 
Fig. 5. Large sac from a species of Olios:—a. A portion of the duct of the 
same, showing the fibrous coat. 
Fig. 6. Peculiar shaped sac, with branched ceca, from Ciniflo atrox. 
_ * Introduction to Entomology, 3rd edit, vol. i. p. 418. 
