498 



SCIENCE. 



[N. S. Vol. III. No. 68. 



works are conspicuous because of magni- 

 tude; the prehistoric works of Papagueria 

 in general are noteworthy in extent, and 

 in that they appear to indicate the exist- 

 ence of a more numerous population than 

 that of historic times who stored and con- 

 trolled storm waters and thus occupied a 

 higher culture-plane than the modern In- 

 dian, Mexican and American inhabitants 

 of the same region. 



During the recent expedition it was 

 ascertained that, while the prehistoric 

 works of Papagueria stretch to the south- 

 western boundary of that territory they do 

 not extend into Seriland, where no ancient 

 works were found except shell heaps, 

 cairns, etc., such as the Seri now accumu- 

 late. Some of the shell heaps are, however, 

 of great volume and extent, and so situated 

 as to prove that they have survived con- 

 siderable geogi-aphic changes ; thus a mound 

 built almost wholly of clam shells (belonging 

 to a series covering several acres) is some 

 60 feet high and over 300 feet in diameter, 

 and is located on a part of the shore where 

 there are now no clam flats, which the 

 waves have invaded until a considerable 

 part of the mound has been swept away— 

 the section thus exposed revealing typical 

 Seri potsherds and stone hammers from 

 top to bottom. So Seriland appears to be 

 an archseologic as well as an ethnic unit, 

 and there is nothing to indicate that the 

 territory was ever held by other people than 

 the ancestors of the modern tribe. 



During the earlier expedition it was ob- 

 served that the flora and fauna of Papa- 

 guara display certain characteristics which 

 were ascribed to the influence of a pecu- 

 liar environment; and during the later 

 expedition further notes relating to this 

 subject were made, and a small collec- 

 tion of plants was gathered and placed in 

 the hands of Professor J. W. Tourney, of 



the University of Arizona, for identification 

 and study. While the observations on 

 plants and animals were in a measure 

 casual and were not guided by expert 

 knowledge, they proved particularly sug- 

 gestive in their bearing on the relations be- 

 tween the human inhabitants of the same 

 region and their environment. These biotic 

 studies indicate that, in sub-desert regions, 

 the development of the individual and the 

 species is determined primarily by a rigor- 

 ous enviroment ; so that the course of de- 

 velopment tends at the same time toward 

 pronounced individuality and toward a 

 complex system of cooperation among di- 

 verse organisms, whereby each immediately 

 antagonizes, but ultimately serves, its con- 

 temporaries. Some of the inferences from 

 the observations of the earlier expedition 

 have already been stated* and need not be 

 repeated ; but many new examples, con- 

 gruous with those previously collected, were 

 noted. 



Among the most interesting observations 

 are those pertaining to the cooperative in- 

 terrelation between animal and vegetal or- 

 ganisms, whereby each depends on the other 

 for existence ; this being the stage of vital 

 cooperation called commensality. The best 

 known examples of commensalitj' are those 

 of the fig and fig insect and the yucca and 

 yucca moth, in which the relation was es- 

 tablished by Riley ; though a still more strik- 

 ing example, in which, however, the relation 

 has not yet been demonstrated, is that of 

 the saguaro, or giant cactus ( Cereus Gigan- 

 teus) and its insect mate. During the re- 

 cent trip two distinct plants were found 

 apparently to represent a still more complex 

 miscigenesis : The cina {Cereus schotti), one 

 of the most abundant cacti of southern 

 Papagueria and Seriland, seems not to 

 flower or fruit under what would commonly 

 be considered normal conditions, but only 



(* ' The Beginning of Agriculture, ' American 

 Anthropologist, Volume VIII., 1895, pp. 350-375.) 



