78 AMERICAN SPIDERS 



The Short-Sighted Hunters. Most of these spiders are nocturnal 

 creatures of the ground that rely almost entirely on touch to inform 

 them of the character of their environment. They test the surface 

 by means of their legs, which act both as organs of touch and of- 

 fensive weapons. Their approach to the female is usually a bold 

 one, since most of them approximate her in size, and a mere touch 

 is sufficient to inform them of her sex and species. Further, this 

 physical contact probably gives the female the same information. 

 Recognition is almost instantaneous and largely based on the chem- 

 ical sense. There remains only for the male to stimulate the female 

 until mating can be accomplished. He does this by stroking and 

 tickling her body, while at the same time maintaining a firm grip 

 on her with his legs or chelicerae, so that she cannot escape. 



The tarantulas are wonderful subjects for the study of mating 

 behavior in the short-sighted spiders. Alexander Petrunkevitch has 

 described the courtship of Dugesiella hentzi thus: 



When the restlessly wandering male happens to touch with 

 his legs some part of the body or a leg of the female, he at once 

 stops short and begins to strike simultaneously and violently 

 with his anterior, sometimes with all four front feet. . . . This 

 continuous beating with the front legs upon the body or legs 

 of the female constitutes the first step in the courtship on the 

 part of the male. In case the female does not attempt to run 

 away, the male soon shifts his position until he is facing the 

 female. The behavior of the female during the first stage of 

 the courtship is composed of two elements. At the first touch 

 she raises the front legs and assumes the attitude of defense and 

 threat. The subsequent touching results in her rising high on her 

 hind legs while still holding up the front legs. Finally, she opens 

 the fangs and the male catches them with the hooks on his front 

 legs. . . . They serve admirably to guard the male against possi- 

 ble injury or even death while at the same time aiding him in 

 the act of coitus. For he now forcibly pushes back the cephalo- 

 thorax of the female with his front legs and drums with the 

 patellas of the palpi on her sternum, all the time advancing. 9 

 The mating that follows lasts only a minute or two, after which 



A. Petrunkevitch, "Sense of Sight, Courtship and Mating in Dugesiella 

 hentzi (Girard), a Theraphosid Spider from Texas," Zool. Jahrbucher Syst., 

 Vol 31, p. 373. 



