THE MONSTERS OF OUR BACK YARDS 



619 



beast of prey which could clear a quar- 

 ter of a mile at a bound. 



It can sit on a branch and throw out 

 an elastic dragline behind strong enough 

 to bear its weight, and by this means it 

 is able to jump at and catch its prey on 

 the rty. regaining its position by climb- 

 ing up the dragline. Add to this that it 

 possesses a pair of powerful hollow 

 fangs, into which poison sacs empty, and 

 a voraciousness which often leads it into 

 cannibalism, and you have a fair picture 

 of this jumping spider, which is one of 

 a thousand species of little creatures 

 found everywhere except in the polar 

 regions. They range in size from a 

 third to a half an inch long and live 

 undei stones and sticks, spending the 

 winter in a silken bag of their own 

 manufacture, but never spinning a web. 

 The males of some species have been ob- 

 served to dance before the females, 

 holding up their hairy legs above their 

 heads to show off their ornamentation. 



THE WOLF-SPIDER {Lycosa carolinensis) , 

 PAGE 620 



This is not the photograph of a polar 

 bear, but that of the wolf-spider, with a 

 battery of eight eyes on the top of its 

 head and poison fangs hanging below. 



Behind and above the fangs and hid- 

 den in their shadow is the creature's 

 mouth — toothless and made for sucking 

 only. W'ith his fangs this wolf-spider 

 kills and crushes his victim ; then he 

 sucks the body dry and throws away the 

 carcass. 



Seen here and there above the body 

 hair are black spines, hollow inside and 

 connected with the nerves of touch. Of 

 his eyes, the two in the center in front 

 are supposed to be for use by day, while 

 all the others are nocturnal, enabling 

 him to stalk his prey at dusk. It is the 

 wolf-spider that often appears at night 

 within the circle of lamplight searching 

 for nocturnal insects. 



The nocturnal eyes are remarkable or- 

 gans, with reflecting structures so placed 

 behind the retina that the light entering 

 the eye traverses the retina twice, and it 

 is supposed that this reflecting structure 

 increases the effect of any faint light, en- 

 abling the creature to "see in the dark." 



This is a hunting spider, chasing its 

 prey through the grass or lurking under 

 stones, especially in damp places. 



It does not spin a web, but lives in a 

 silk-lined hole 6 or 8 inches deep, which 

 it digs in the ground, and around the en- 

 trance to which, out of sticks and grass, 

 it builds a turret or watch-tower, from 

 which it can see its prey more readily 

 than from the ground. These spider 

 holes are common in the meadows of 

 Maryland. 



In form and color the wolf-spider re- 

 sembles the famous tarantula of south- 

 ern Europe, the bite of which was sup- 

 posed to cause the tarantella, or dancing 

 madness ; but it is as harmless as a but- 

 terfly, and indeed Dr. Comstock, who is 

 the authority on spiders, believes that no 

 spiders in the Northern States are poi- 

 sonous to man. 



SKELETON OF A WOLF-SPIDER {LycOSa 



punctulata) , page 622 



This photograph is the outer skeleton 

 or shell of a small wolf-spider which I 

 found clinging to the focusing cloth of 

 my camera after it had been lying on the 

 grass. 



W'xih us the bony skeleton is internal 

 and grows as we grow. With spiders the 

 skeleton is a tough, bony structure, which 

 cannot change ; so that the young, rapidly 

 growing spider soon finds his shell too 

 tight for him, and. like a crab, he bursts 

 his shell and i)ulls his soft body from 

 each leg and complicated cavity. 



This process seems marvelous, but is 

 really comparatively simple when we re- 

 alize that before the old shell is cast off 

 it is loosened from the new skin by the 

 moulting fluid which is excreted from 

 glands opening through this new skin. 



After the old skin is loosened it splits 

 along the sides of the body and in front 

 of the eyes, the slit being just above the 

 legs and jaws, and that portion of the 

 old skeleton which had covered the back 

 is lifted off like a lid. The new skin, at 

 first elastic enough to accommodate the 

 increased size of the body, soon becomes 

 hardened like the old, and must in its 

 turn be shed. 



Imagine, if you can. the surprise of a 

 wolf-spider who in running through the 



