lotka: efficiency in organic evolution 365 



labor Li is spent in maintaining a parameter Xi at the 1 



value Xi 



labor Lo is spent in maintaining a parameter X2 at the | 



value Xo } {2) 



etc., etc., etc., etc., etc. 



labor Lj is spent in maintaining a parameter Xj at the 1 



value Xj J 



Now it will immediately be seen that the fitness of the indi- 

 vidual, his adaptation to his environment, in so far as it depends 

 upon the activities defined as above, will depend on two factors : 



1 . On the manner in which the individual distributes his labor 

 among the several pursuits indicated or, in other words, on the 

 proportion 



Li : Lo : . . . iL, (3) 



2. On the productivity or productive efficiency of the individual 

 in each pursuit, as measured by 



Ej = ^f^' (4) 



Xj — Cj^ being the increment in Xj produced by labor Lj per unit 

 of time.^ 



It will be seen that the factors (1) and (2) correspond in a 

 way to certain points in our tabular analysis of the influence of 

 various errors on the efficiency of the individual. But instead 

 of considering individual errors we have lumped them together 

 in a statistical way, so that errors of observation and operation 

 find their expression in the corresponding values of the pro- 

 ductive efficiencies (which are of course diminished by every 

 such error), while errors of valuation find their expression in 

 the proportion 



L/i '. L/o '....' L/j 



^ The constant Cj is introduced because for some commodities (and for most 

 discommodities) Xj is not zero when Lj is zero, i.e., some of the commodity 

 "grows" spontaneously without the intervention of the interested individual. 



8 In case Xj is of the nature of a "discommodity," Ej is of course negative, 

 as in the case of the example cited above, namely, if Xj is the deathrate from 

 malaria. 



