( 5 ) 
and iinlefs I am deceived, even the diftinguifliing marks of the young Spider before it is 
hatched. When the infe6l is hatched, this Ikin collapfes into a fhrivelled bladder. 
29. In the hinder part of the abdomen in both fexes, there are fome prominent tubercles, 
through which they emit the threads with which they make the webs ; and as the tubercles 
vary in the different fpecies, I fliall take an opportunity of relating my obfervations on them; 
and in the defcription of the Water Spider, I fliall fhew that the tubercles ferve alfo for the 
purpofe of refpiration. 
30. In the midfl of the tubercles, and concealed amongfl them, lies the aperture of 
the anus. 
31. The shell, skin, or Epidermis, which Spiders caft, is horny and tranfparent, yet 
cartilaginous, fliewing the fize of the animal in the thorax, legs, eyes, arms, and holders, and 
even the claws ; but the covering of the abdomen is a pellicle or thin fkin, which does not re- 
tain its fliape, but all contrafts in wrinkles. The Spider, when about to caft its fkin, feeks 
out a proper place where it may lie torpid, wrapped up in its web. The whole fliell of the 
thorax being then broken off, is feparated from the limbs, adhering only a little by the hinder 
part, the fore part being bent upwards. At this time the animal is in fuch a lethargic and 
languid ftate as not to be able to defend itfelf, even againft a gnat; at length it comes to itfelf 
again ; and as far as its weak ftate will permit, begins to fhew a little agility by kicking and 
pulling ; refting a while between every attempt, and then going to work again, till at laft it 
has extricated itfelf entirely from the old fkin ; but fo great is the debility under which the 
animal ftill labours, that it is yet unable to go the length of its body from the flough ; it 
therefore remains fufpended in its web, till the air has fufficiently dried and ftrengthened its. 
fkin, when regaining its ufual powers, it refumes its wonted manner of living, clad in its 
new habit or fkin. 
c 
PARE 
