196 AMERICAN SPIDERS 



The elongate cephalothorax is usually high and narrowed in front, 

 and bears eight eyes whose size and position immediately distinguish 

 the lycosids from almost all other spiders. Set close together on the 

 lower part of the face is a row of four small eyes that point for- 

 ward and slightly to each side. Immediately above these are two 

 very large eyes that point forward, and farther back on the dorsal 

 part of the head are two large eyes that look upward. The spider 

 is thus able to see in four directions, and, because of the size and 

 acute vision of some of these batteries, can perceive moving animals 

 at a distance of several inches. The legs and chelicerae are robust, 

 as befits such powerful hunting creatures; the oval abdomen is of 

 moderate size. 



The capture of prey by the wolf spider is marked by vigor and 

 power. The spider pounces upon its victim and, holding the body 

 in its strong front legs, bites and crushes with its stout chelicerae. 

 The capabilities of this rapacious hunter are not without limitation, 

 however, when contrasted with those of higher animals. Although 

 keen and long-sighted among spiders, its vision hardly merits com- 

 parison with that of many insects. Its prey is perceived by sight, 

 but the character of the moving object is probably not at all evident 

 until the spider touches it. The diurnal lycosids are undoubtedly 

 able to make greater use of their eyes than the nocturnal types; 

 but these latter are conditioned to respond to the slightest disturb- 

 ance of the soil of their hunting ground. Furthermore, the wolf 

 spiders have a tapetum that reflects light rays back through the eye 

 retina, and presumably improves their night vision. 



The female wolf spider is, in the fashion of her sex, a creature 

 of variable temper. Notorious for her rapacious activities, she 

 nevertheless displays a solicitude for her eggs and young that can 

 scarcely be matched by any other spider. The mother Pardosa, 

 which it will be recalled encloses her eggs in a carefully molded 

 spherical bag, attaches the sac to her spinnerets and drags it around 

 with her (Plate XXVI) wherever she goes. It make no difference 

 that it is often as large as she is; this egg bag is a precious thing to 

 her; she will defend it with her very life, and will fight viciously 

 to retain it. Her instincts are most powerful ones, but ironically 

 she is easily fooled and will accept for a time, and almost without 

 question, a substitute sac from which the eggs have ben pilfered, a 

 piece of cork, or a wad of paper or cotton of the proper size and 

 shape. 



After two or three weeks, her young develop to a point where 



