SOME SPECIFIC CHARACTERS 127 



or structural components. But it is a more correct state- 

 ment of the case to say that natural selection or survival 

 preserves not the fittest, but the least fit possible under the 

 circumstances — namely, all those which, however great 

 their divagations and eccentricities of variation in other 

 respects, yet at the same time attain to a minimum 

 standard of qualification in those structures (or inner 

 chemical qualities) essential for success in the competi- 

 tion for safety, food and mating determined by the 

 particular conditions in which the competition is taking 

 place. Consequently forms which are meaningless so far 

 as standards of utility or "life-saving" are concerned, and 

 are rightly described as grotesque, monstrous, gigantic or 

 dwarfed — excessive (as compared with more familiar 

 kinds) in hypertrophy or atrophy of their colouring and 

 clothing, or of out-growths such as leaves of plants and 

 limbs, jaws or other regions of the body of animals — are 

 found existing in various degrees of eccentricity in every 

 class of both plants and animals. Among animals such 

 tolerated " exuberances of non-significant growth " are 

 more striking than in plants. The group of fishes seems 

 to be especially privileged in this way. They are freely 

 variable in the position of the fins, the suppression or 

 exaggeration of them, as well as of the scales on the 

 surface of the body {e.g. leather carp and mirror carp). 

 Take, for example, the mackerel and the salmon as 

 standards of utilitarian adaptation of the body to an active 

 life in sea or river, and then compare with theirs the 

 astounding proportions of the sun-fish (Orthagoriscus) like 

 a cherub " all head and no body," or the almost in- 

 credible Pteraclis — with its little body framed immovably 

 between a huge dorsal and a huge ventral fin (see figures 

 on p. 130). The fin-like crest of enormous size on the 

 back of the great extinct lizard Dimetrodon of the 

 Permian age supported by long bony spines is a similarly 



