XVIII THE PROBLEM OF UTILITY 391 



of recognition, which explains both their comparative 

 stability in each species and their distinctness in allied 

 forms. ^ 



The next alleged cause, Isolation, I do not admit to be 

 a vera causa at all, for reasons already given. It is, at 

 most, an aid to the differentiation of new species by 

 natural selection. 



The last alleged cause, the Law^s of Growth, can never, 

 of itself, account for specific characters, but only for those 

 structural and histological peculiarities of organisms 

 which characterise the higher groups such as classes and 

 sometimes perhaps orders and families ; and even these 

 must always, when they first originated, have had a 

 utilitarian character, since it is almost impossible to 

 conceive that the details of structure of the various tissues 

 or organs produced under the action of these laws were 

 absolutely indifferent to the well-being of the organism. 



If, then, we admit, as I do admit, that certain growths 

 app^dages, or markings, which are of no use to the 

 organism, do occasionally appear, no agency has been ad- 

 duced which could, first, cause these useless characters to 

 appear in every individual of a species, and then totally 

 cease to appear whenever any portion of this species is 

 selected and slightly modified so as to occupy a new 

 place in nature or to save itself from extinction by some 

 new enemy. Whenever useless characters are said to be 

 " specific," it seems to be forgotten that one species has 

 always passed continuously into another by a process of 

 normal individual variation and survival of the fittest. 

 There is no chasm in such a process, no sudden transition 



^ Since this chapter was written I have carefully studied Professor 

 Weismann's new theory of "Germinal Selection," which seems to 

 me to have a high degree of probabilit}', and which, if true, enables 

 us to explain two phenomena which have not hitherto been fully 

 explicable. These are (1) the complete or almost complete disappear- 

 ance of many characters which have become useless ; and (2) the 

 development of secondary sexual characters far beyond the point of 

 utility as recognition-marks, and, apparently, up to the extreme 

 point of incipient hurtfulness. It thus furnishes the one link necessary 

 in the chain of argument proving that these secondary sexual characters 

 are explicable without calling in the very problematical agency of 

 female choice. 



