540 



ANNUAL, REPORT SMITHSONIAN INSTITUTION, 1908. 



rays spreading from a common center (pL 9, fig. 1), or in 

 pectinate fasciles with the radial spines arranged in two rows 

 on each side of a longitudinal axis (pi. 2, fig. 6). In addition 

 to the radial spines, there are usually erect or projecting cen- 

 tral spines, either straight and rigid or curved. One of the most 



striking arrangements is that of spines of 

 Myrtillocactus geoTnetrizans^ in which the 

 v\ \\ central spine resembles the blade of a 



yQ Wn dagger and the radials a guard for the 



hilt (fig. 4, p. 539). 



Cactus spines have been utilized by 

 primitive tribes for various purj^oses. 

 Dr. Edward Palmer has described the 

 manufacture of curved fishhooks from the 

 spines of a certain Echinocactus b}^ the 

 Mohave Indians of the Colorado Hiver." 

 Fishhooks with straight shanks of bone 

 and barbs of cactus spines were dug up 

 by the writer from prehistoric graves at 

 Arica, on the coast of Chile, in 1887. 

 They w^ere associated with other articles 

 made of cactus spines, such as needles 

 and combs. In December, 1891, the writer assisted at the opening of 

 several other graves at Iquique, on the same coast, in which not only 

 hooks and needles of the same description were found, but interesting 

 examples of the application of cactus spines to the mending of slits 

 in sealskins which had been used for covering the graves. In these 

 the spines were stuck like awls 

 through both margins and allowed 

 to remain with the ends projecting. 

 Around the ends thread had been 

 passed in a zigzae manner and 



Pig. 5. — Cactus-spine fishhooks. 



drawn tight, thus closing the slits 

 tightly and efiectively. 



FLOWERS. 



Fig. 6. 



Leather repaired witli cactus 

 spines. 



In most genera the flowers issue 

 from the upper part of the areoles, 

 but in some species of Mamillaria and allied genera they grow 

 from between the mammillae, or from near their base at the 

 end of a groove extending backward from the areole. Usually 

 they are solitary and sessile, but in the genus Pereskia they are 

 peduncled and clustered. In nearly all genera they are conspicu- 



<* See American Naturalist, Vol. 12, p. 403. 1878. 



