NATURAL SELECTION 181 



In some cases variations or individual differences of a 

 favorable nature may never have arisen for natural se- 

 lection to act on and accumulate. In no case, probably, 

 has time sufficed for the utmost possible amount of de-i 

 velopment. In some few cases there has been what we 

 must call retrogression of organization. But the main 4 

 cause lies in the fact that under very simple conditions 

 of life a high organization would be of no service — pos- 

 sibly would be of actual disservice, as being of a more ' 

 delicate nature, and more liable to be put out of order I 

 and injured J V 



Looking to the first dawn of life, when all organic 

 ' beings, as we may believe, presented the simplest struc- 

 ture, how, it has been asked, could the first steps in the 

 advancement or differentiation of parts have arisen? Mr. 

 Herbert Spencer would probably answer that, as soon as 

 simple unicellular organism came, by growth or division, 

 to be compounded of several cells, or became attached to 

 any supporting surface, his law "that homologous units 

 of any order become differentiated in proportion as their 

 relations to incident forces become different" would come 

 into action. But as we have no facts to guide us, spec- 

 ulation on the subject is almost useless. It is, however, 

 an error to suppose that there would be no struggle for 

 existence, and, consequently, no natural selection, until 

 many forms had been produced: variations in a single 

 species inhabiting an isolated station might be beneficial, 

 and thus the whole mass of individuals might be modi- 

 fied, or two distinct forms might arise» But, as I re- 

 marked toward the close of the Introduction, no one 

 ought to feel surprise at much remaining as yet un- 

 explained on the origin of species, if we make due 



