102 THE ORIGIN OF SPECIES 



been preserved to the present day, from inhabiting confined or 

 peculiar stations, where they have been subjected to less severe 

 competition, and where their scanty numbers have retarded the 

 chance of favorable variations arising. 



Finally, I believe that many lowly organized forms now exist 

 throughout the world, from various causes. In some cases, varia- 

 tions or individual differences of a favorable nature may never 

 have arisen for natural selection to act on and accumulate. In no 

 case, probably, has time sufficed for the utmost possible amount 

 of development. In some few cases there has been what we must 

 call retrogression of organization. But the main cause lies in the 

 fact that under very simple conditions of life a high organization 

 would be of no service, — possibly would be of actual disservice, as 

 being of a more delicate nature, and more liable to be put out of 

 order and injured. 



Looking to the first dawn of life, when all organic beings, as we 

 may believe, presented the simplest structure, how, it has been 

 asked, could the first step 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 inci- 

 dent forces become different" would come into action. But as we 

 have no facts to guide us, speculation on the subject is almost use- 

 less. 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 in- 

 habiting an isolated station might be beneficial, and thus the whole 

 mass of individuals might be modified, or two distinct forms might 

 arise. But, as I remarked toward the close of the introduction, no 

 one ought to feel surprise at much remaining as yet unexplained 

 on the origin of species, if we make due allowance for our pro- 

 found ignorance on the mutual relations of the inhabitants of the 

 world at the present time, and still more so during past ages. 



CONVERGENCE OF CHARACTER 



Mr. H. C. Watson thinks that I have overrated the importance 

 of divergence of character (in which, however, he apparently be- 

 lieves), and that convergence, as it may be called, has likewise 

 played a part. If two species belonging to two distinct though 

 allied genera, had both produced a large number of new and di- 

 vergent forms, it is conceivable that these might approach each 



