196 



The Journal of Heredity 



compounds from the earliest or<;:anic 

 series synthesized on the earth to the 

 livin}^ matter of the jiresent day. 

 The immortaHty of Hvin^' matter dates 

 back before the orij^nn of the cell. 



Another property or characteristic of 

 living matter must have made its ap- 

 pearance here, since it is present in cer- 

 tain constituents of the environment 

 (Henderson), and that is the i)roperty 

 of regulation. I do not mean regulation 

 in ])recisely the same sense in which it 

 has been used by zoologists and botanists 

 to denote control of form and size and 

 other morphological characters, but 

 regulation of the physico-chemical con- 

 ditions of the organism as well. Sta- 

 bility of physico-chemical conditions 

 within certain limits is inherent in the 

 environment, but, as has been shown, 

 the \'ariations may be greater in the 

 environment than in the organism. It 

 is characteristic of some organic com- 

 pounds, and i^articularh^ of those in 

 living matter, that slight changes in the 

 external conditions bring about con- 

 siderable changes in the compounds 

 them.selves. This is the ])henomenon 

 of irritability. vSomc ])rovision for 

 guarding against the effects of such 

 changes on the ])art of those aggregates 

 of organic comjjounds which formed the 

 first stages in the evolution of living 

 matter — a power of regulation of the 

 internal conditions — must have been an 

 early acquisition. The known ]jhysico- 

 chemical properties of certain constitu- 

 ents of the environment afford us at 

 least some basis for the ex])lanation of 

 the i)roce.ss of regulation in living matter 

 (Henderson). So important for pur- 

 jjoses of evolution is this property of 

 regulation that I would consider it as 

 one of the fundamental jjrojjerties of 

 living matter. We should clearly recog- 

 nize then, the ])robability of the early 

 ])artici])ation of two fundamental i)r()]j- 

 erties of living matter — irritability and 

 the regulation of internal conditions — 

 in the evolution of living organisms. 

 Great as have Ijcen the advantages to 

 the individual of this jjroperty of regu- 



lation of internal conditions, its i)osses- 

 sion also entails certain disadvantages. 



CONDITIONS OF LIKI-: 



The sur\-ival of any ijarticular com- 

 I)lex of organic compounds, and the 

 po.ssibility of its further develoi)ment to 

 still more complex forms must have 

 Ijcen de])endent upon various jiroperties, 

 in addition to irritability and the 

 regulation of internal conditions. The 

 ability to form comjjounds of greater 

 and greater comjjlexity was one. The 

 number of compounds formed, while 

 great and varied, was subject to cer- 

 tain limitations because of the nature 

 and properties of the substances enter- 

 ing into them. The direction of varia- 

 tion was subject to similar limitations, 

 and we may imagine that orthogenesis, 

 in a form dictated by the properties of 

 matter and the conditions in the en- 

 vironment, was oi)erative in the early 

 stages of cA'olution. Early in the pro- 

 cess of evolution, the question of fitness 

 entered in, and we are confronted with 

 the i^roblem of selection. "The princi- 

 ])le of the survival of the fittest aj^plies 

 with all its force to such initial steps 

 in the evolution of life. The more 

 completely self-regulating inixtures 

 would outlast the others."^ It was not 

 many years ago when we read that " the 

 true Darwinism, that is, the tendency 

 which ascribes to natural selection the 

 chief role in the origin of adaptations 

 has, in Germany at least, almost no 

 adherents."'' But whether selection be 

 the chief factor in the origin of adapta- 

 tion or not, the oi)eration of the princi- 

 ple seems clear in the early stages of 

 evolution, and it is not readily ajiparent 

 at what i)oint in the process selection 

 has ceased to act. 



Whether or not chromosomes existed 

 Ijcfore the early stages in the evolution 

 of living inalter which led to the 

 formation of cells, we do not know, 

 but .some of the stages in the synthesis 

 must ha\'e l)een devoid of them. Some 

 degree of heredity must ha\'e been ])os- 

 sible in these earliest stages by other 



'Goodrich, op. cil., ]). 17. 



* "Dcr cif^cntlidu' Darwinisnnis, d.h. die RiiliUinjj, wekhc dor natiirliclK'n Zuchlwalil die 

 lIaui)lrol]c' l)ci dcm Zu.standekoiniiifn diT Ani)a.ssiin)^i'n zuschrdht, in Deutschland wcniRstcns 

 fast keine Vertreter mclir hat." Cioi-lnl, (|U()U-d l)y Ifiistn, p. ?>. 



