ADMINISTRATIVE REPORT XV 



meats, ;ire substantial!)^ alike from tribe to tribe; though it 

 is noteworthy that in each trilje there is a diversity grov?ing 

 out of the age of the ap})aratus, or the degree of development 

 by use. Thus it is found that the nether millstone, which may 

 be either a ledge or other mass in place of a portable bowlder, 

 is, in tlie earlier stages of use, a flat or slightly concave metate, 

 which after more extended use becomes a deeply concave 

 metate, still later a shallow mortar, and at length a deep 

 mortar, which niay eventually be worn through if tlie original 

 mass is not more than 9 to 16 inclii'S in thickness; while the 

 grinding'-stone concordantly changes from a simple roller or 

 crusher to a mano (or muller), and finally to a jsestle, at first 

 broad and short, but afterward long and slender. It follows 

 that in this region the northern device of the mortar and the 

 southern device of the metate overlap; yet it is much more 

 significant that the overlapping is essentially genetic and only 

 incidentallv geographic. Not infrequently the genesis of an 

 individual mill corresponds with the rise and passing of a 

 fainily; the young woman may begin life with a bowlder 

 having one flat side and a few river-woni cobbles as a mill; 

 the bowlder is then used as a metate and the cobbles as nnil- 

 lers; gradually the mill develops into a mortar with a well- 

 rounded and polished pestle, both shaped chiefly by wear, 

 perhaps supplemented by slight dressing. On this the matron 

 grinds vigorously in her old age for the support of her 

 daughters and their husbands and the growing grandchildren; 

 and on her death apjjareiitly the pestle is broken and the 

 bottom is knocked out of the mortar. Neglecting the final 

 act, the individiial growth of the primitive mill well epitomizes 

 the phylogeny of its species, and demonstrates that in general 

 the mortar must be regarded as the diff'erentiated and even- 

 tualh- degraded off'spring of a metate-like prototype, whence 

 sprang also the metate along one line and the quern and its 

 derivatives along another. It is particularly significant, too, 

 that the milling apparatus still used by the Oalifornian natives 

 consists initially of naturally-formed ledges or bowlders, with 

 stream-worn cobbles for grinders, and that both bowlder and 

 cobble are, for the most part, shaped gradually l)y wear, with- 



