SCHEFFER : COCOONING HABITS OF SPIDERS. 89 



eggs and the two are united by their overlapping edges. The 

 result is a biscuit-shaped affair in some cases ; in others a 

 cocoon that is almost perfectly globular. These are the por- 

 table cocoons referred to above. Within the outer envelope of 

 the homogeneous type of cocoon may be one or more others, 

 and on the inside, surrounding the eggs, is often a quantity of 

 fluffy packing. 



The contents of the cocoon next claim a share of our atten- 

 tion. Three conditions of the egg-mass obtain among the 

 various species of spiders — the eggs may be free to roll about 

 like so many dry peas, they may be entangled and held together 

 by fine threads of silk, or they may be glued together into a 

 more or less compact ball by a viscid secretion that hardens as 

 it dries. This last condition seems to be an especially favorable 

 one in which to pass the winter. Evidence of this is supported 

 by the egg-masses of Araneus trifolium and the Spectacled spider 

 of the East, which are not only held together but covered with 

 a limy looking secretion. 



The number of eggs varies greatly, depending largely, no 

 doubt, on the chances for hatching and survival of the brood. 

 We accordingly find the number greater when the eggs must 

 pass the winter unhatched, or when they are not guarded by 

 the mother spider. That this is not always true, however, is 

 shown by the fact that some spiders whose eggs pass the winter 

 without hatching lay but a few. The Triangle spider, for in- 

 stance, encloses less than a dozen eggs in her compact, scale-like 

 cocoon ; but the latter is rendered so secure by reason of its 

 protective coloring, in addition to other things, that probably 

 nearly all the eggs hatch in the spring. Certain spiders which 

 carry their eggs about, or shut themselves up in a cell with 

 them, lay not more than three to five. The other extreme is 

 represented by species such as Argiope aurantia, whose cocoons, 

 containing from 1000 to 1200 eggs, hang unprotected from the 

 tops of dead goldenrods through the storms of winter. 



The large, burrowing Wolf spider, which sometimes lives in 

 our gardens, lays from 500 to 600 eggs, enclosing them in a 

 globular cocoon. For this treasure the mother will fight des- 

 perately, refusing to surrender or desert it even when her legs 

 are torn from her body. Her devotion is born of instinct, how- 

 ever, and not of reason ; since it is an easy matter for an 



