PREDATORY AND INDUSTRIAL SOCIETIES. 731 



and Samnites, preceded the first ascending stage of the Roman civ- 

 ilization. And our own country, peopled by different divisions of the 

 Aryan race, and mainly by varieties of Scandinavians, again illus- 

 trates this eft'ect produced by the mixture of units sufficiently alike to 

 cooperate in the same social system, but sufficiently unlike to prevent 

 that social system from becoming forthwith definite in structure. 



Admitting that the evidence where so many causes are in opera- 

 tion cannot be satisfactorily disentangled, and claiming only proba- 

 bility for these inductions respecting social constitutions, it remains 

 to point out their analogy to certain inductions respecting the consti- 

 tutions of individual living things. Betw T een organisms widely un- 

 like in kind, no progeny can arise : the physiological units contrib- 

 uted by them respectively to form a fertilized germ cannot work to- 

 gether so as to produce a new organism. Evidently as, while multi- 

 plying, the two classes of units tend to build themselves into two dif- 

 ferent structures, their conflict prevents the formation of any struct- 

 ure. If the two organisms are less unlike in kind belonging, say, to 

 the same genus though to different species the two structures which 

 their two groups of physiological units tend to build up being toler- 

 ably similar, they can, and do, cooperate in making an organism that 

 is intermediate. But this, though it will work, is imperfect in its 

 latest-evolved parts : there results a mule incapable of propagating. 

 If, instead of different species, remote varieties are united, the inter- 

 mediate organism is not infertile ; but many facts suggest the conclu- 

 sion that infertility results in subsequent generations : the incongru- 

 ous working of the united structures, though longer in showing itself, 

 comes out ultimately. And then, finally, if, instead of remote vari- 

 eties, varieties nearly allied are united, a permanently-fertile breed 

 results ; and, while the slight differences of the two kinds of physio- 

 logical units are not such as to prevent harmonious cooperation, they 

 are such as conduce to plasticity and unusually vigorous growth. 



Here, then, seems a parallel to the conclusion indicated above, 

 that hybrid societies are imperfectly organizable cannot grow into 

 forms completely stable ; while societies that have been evolved from 

 mixtures of nearly-allied varieties of man can assume stable struct- 

 ures, and have an advantageous modifiability. 



We class societies, then, in two ways ; both having to be kept in 

 mind when interpreting social phenomena : 



First, they have to be arranged in the order of their integration, 

 as simple, compound, doubly-compound, trebly-compound. And, 

 along with the increasing degrees of evolution implied by these as- 

 cending stages of composition, we have to recognize the increasing 

 degrees of evolution implied by growing heterogeneity, general and 

 local. 



Much less definite is the division to be made among societies ac- 

 cording as one or other of their great systems of organs is supreme. 



