THE ORIGIN OF SPECIES. 57 



5. That the process of selection of individual fluctuations can, at 

 best, only keep the species up to an artificial standard that will be lost 

 as soon as a rigorous process of selection ceases, has been shown by 

 de Vries and others. The permanent inheritance of each species can 

 not have been acquired in this way. Unless, for example, those in- 

 dividuals whose life is somewhat longer or shorter were being con- 

 stantly destroyed in every generation the little would soon be lost that 

 had been so laboriously gained. It is needless to point out that no 

 such process is taking place on a scale sufficient to regulate the evolu- 

 tionary process. 



6. The length of life of a species is something that is as char- 

 acteristic of the species as any of its structural or physiological prop- 

 erties. To state that the duration of life can not be supposed to be 

 the result of physiological processes is not simply paradoxical but 

 absurd. The paradox and also the absurdity disappear as soon as we 

 recognize the fact that the length of life is a characteristic of each 

 new species and is a purely physiological process. Those new 

 elementary species whose physiological processes fulfill the conditions 

 of a certain environment survive, those that do not perish; and there 

 is no subsequent lengthening of one character and shortening of 

 another, as on a sliding scale, to fit the new form in all details to its 

 new environment. The length of life is predetermined with the advent 

 of the new form, and is not subsequently regulated for the benefit of 

 that particular species. From this point of view we get a simple and 

 clear analysis of the problem, while that which Weismann maintains 

 leads only to an unmeaning ' paradox.' 



It seems to me that the method of the Darwinian school of look- 

 ing upon each particular function, or structure, of the individual as 

 capable of indefinite control through selection is fundamentally wrong. 

 For instance, in regard to the number of eggs characteristic of each 

 species, it is assumed that \he output is also regulated by means of selec- 

 tion. On the contrary it appears to me that the power to produce a 

 certain number of eggs is one of the fixed characteristics of each species 

 that appears, and is not increased or diminished by external needs. 

 The number of individuals that reach maturity will stand, therefore, 

 as a measure of how far a new species is from the beginning adapted 

 to the old environment, or to the new one in which it establishes itself. 

 There may be a wide range of perfection in this respect, for there are 

 some species that produce few eggs, but succeed in bringing a large 

 number of them to maturity, and there are other species which, despite 

 the countless number of eggs that they produce, only succeed in barely 

 holding on to existence. Since the great majority of lower animals 

 and plants produce large numbers of eggs we may infer that the 

 arrangement for propagation, while it suffices to keep the species in 



