158* THE SERI INDIANS [eth.ann.17 



do swift stroke and strong grasp and dexterous digitation, are mainly 

 such as urge manual development more strenuously thau would be 

 normal among tribesmen connected with their environment through 

 the medium of tools. The demand for manual strength and skill is 

 intensified among the Seri by both natural and domestic conditions; 

 the ever-ready (and almost the sole) material suitable for simple 

 adjuncts to the baud abounds iu the form of wave- worn cobbles; these 

 cobbles are easily usable in such wise as to serve all ordinary i)nrposes, 

 and their abundance discourages the production of more highly differ- 

 entiated tools; while their habitual use promotes manual strength and 

 deftness, coupled with that digital freedom (required, for example, in 

 grasping a ball) which most clearly distinguishes f he human hatul from 

 the subhuman paw. Conjoined with these natural conditions are 

 demotic demands tending to cultivate mauual fitness and eliminate the 

 manually unfit; for, iu addition to the direct industrial premium on dex- 

 terity, through which the dexterous survive while the clumsy starve, there 

 is a special premium growing out of the marriage custom, through which 

 only the manually efficient (and at the same time morally acceptable) 

 are put in the way of leaving lines of descendants.' Naturally, in view 

 of the combination of factors, all traceable directly or indirectly to 

 environmental conditions, the Seri afford a peculiarly striking example 

 of cheirizatiou extended to an entire tribe (if not to a genetic stocdc of 

 people) — indeed the remarkably developed Seri hands and feet first 

 saggested the importance of this process of human development and 

 led to its formal characterization. 



Accoidiugly, the robust-bodied and slender-limbed j-et big-fisted and 

 big-footed Seri seem to be adjusted, so far as several of their more 

 striking somatic characters are concerned, to distinctive habits them- 

 selves reflecting a distinctive habitat; and the coincidences ap|)ear to 

 reveal and establish the law of interaction between the human organism 

 and its environment — an interaction effected through the habits and 

 hence through the uornuil functioning of the individual organisms as 

 constrained through their collective relations. And recognition of the 

 law of interaction opens the way to consideration of other correspond- 

 ences between structures and functions and environing conditions. 



Conspicuous among the more strictly fuuctioual traits of the Seri is 

 the intensity of action characteristic especially of the warriors, though 

 in less degree of the entire tribe — an intensity made all the more strik- 

 1 ing by contrast with the extreme inertness between stresses. Mani- 

 festly the capacity for concentrated effort is in harmony with the 

 tribal habits, themselves reflecting habitat. The resource of prime 

 importance in Seriland — that which directly and constantly conditions 

 the very existence of human inhabitants — is potable water. This prime 

 source of life is- too heavy to be transported and too unstable to be 

 stored with the facilities of primitive culture, yet it is always within 

 reach of an organism strong enough to journey ten or twenty or fifty 



> The mantal customs of the tribe are described postea, pp. 279-287. 



