418 AMERICAN SPIDERS AND THEIR SPINNINGWORK. 



disturbance of tlie surrounding foliage. (See Fig. 356.) Her first impulse 

 at the approach of what she regards as danger to her offspring, is to 

 seize the little ball and carry it away to another part of her snare, or 

 simply to interpose her own person between it and threatened peril, or at 

 least to secure it by her own personal possession. 



Now, it has already been shown (see pages 119, 120) that certain spe- 

 cies of Linewcavers have acquired the habit of permanently cariying 

 about their cocoons in their jaws and under their legs. This is their 

 method of protecting their offspring from assail of enemies. The same 

 habit, with varying methods, prevails with certain Laterigrades, with most 

 Citigrades, and perhaps also with some Tunnelweavers. May it not be 

 that this fixed habit of protecting cocoons by personal possession may 

 have originated from such occasional acts as that common with Theridium 

 differens, and which, by transmission and gradual growth, have come at 

 last to be characteristic ? 



