126 AMERICAN SPIDERS 



When a Grammostola and a young snake are put in a cage 

 together, the spider tries to catch the snake by the head, and 

 will hold on in spite of all efforts of the snake to shake it off. 

 After a minute or two, the spider's poison begins to take effect 

 and the snake becomes quiet. Beginning at the head, the spider 

 crushes the snake with its mandibles and feeds upon the soft 

 parts, sometimes taking twenty-four hours or more to suck the 

 whole animal, leaving the remains in a shapeless mass. 21 



One of the interesting bits of folklore prevalent in Mexico and 

 Central America is the legend of the matacaballo. For many years 

 it has been a general belief that tarantulas bite the fetlocks of mules 

 and horses and cause the loss of the hoof. According to the story, 

 the spider hunts out the sleeping animal at night and takes a narrow 

 strip of hair from above the hoof for its nest building, using an acid- 

 like secretion to make the hair slough off more easily. The site of 

 the injury then becomes inflamed, infection occurs, and the hoof is 

 lost. In another version, all goes well unless the spider is disturbed 

 and bites the hoof. In order to prevent hair clipping by the mata- 

 caballo y the natives run their animals through a footbath of water 

 covered with about an inch of crude oil. The tarantulas do not like 

 oil-covered hair, so the animals gain temporary immunity from the 

 presumed scourge. 



It is now known that this often fatal disease is actually caused by 

 a bacillus that is very prevalent in the soils of Central America. 

 During the rainy season, the skin of the hoof becomes chapped and 

 the bacillus is able to enter through small abrasions. Needless to 

 say, tarantulas use only their own white silk for their nests. 



THE ATYPICAL TARANTULAS 



One of the two principal branches of the My galomorphae has 

 culminated in the Atypidae, the purse- web spiders; they are the 

 namesakes of the series known as "the atypical tarantulas." This 

 series includes the most generalized of all living spiders, the liphi- 

 stiids (family Liphistiidae) , which have changed little since the 

 late Paleozoic and are the last remnant of an ancient group that 



21 J. H. Emerton, Psyche, 1925, Vol. 39, p. 60. (Part of English abstract of 

 part of article by Vital Brazil and J. Vellard, Memorias do Institute do 

 Butantan, 1925, Vol. II, and 1926, Vol. III.) 



