30 David Starr Jordan 



It is ill the cities where the influences which tend to the 

 modernization and concentration of the characters of the spe- 

 cies, that the intensification of human powers and their adap- 

 tation to the various special conditions go on most rapidly. 

 That this intensification is not necessarily progress either 

 physical or moral is aside from our present purpose. 



It is in the cities where those characters and qualities not 

 directly useful in the struggle for existence are first lost or 

 atrophied. 



Conversely it is in the "backwoods," the region most 

 distinct from human conflicts, where primitive customs, an- 

 tiquated peculiarities, and useless traits are longest and most 

 persistently retained. The life of the backwoods will be not 

 less active and vigorous, but it will lack specialization. 



It is not well to push this analogy too far, but we may per- 

 haps find in it a suggestion as to the development of the eels. 

 In every cit}' there is a class which partakes in no degree of 

 the general line of development. Its members are specialized 

 in a wholly different way, thereby taking to themselves a field 

 which the others have abandoned, and making up in low cun- 

 ning what they lack in strength and intelligence. 



Thus among the fishes we have in the regions of closest 

 competition a degenerate and non-ichthjnzed form, lurking in 

 holes among rocks and creeping in the sand, thieves and 

 scavengers among fishes. 



The eels fill a place which would otherwise be left unfilled. 

 In their way, they are perfectly adapted to the lives they 

 lead. A multiplicity of vertebral joints is useless to the 

 t5rpical fish, but to the eel strength and suppleness are every- 

 thing, and no armature of fin or scale or bone so desirable as 

 its power of escaping through the smallest opening. 



It may be too that, as rovers in the open sea, the strong, 

 swift members of the mackerel family find a positive advan- 

 tage in the possession of many vertebrae, and that to some 

 adaptation to their mode of life we must attribute their lack 

 of " ichthyization " of the skeleton. But this is wholly hypo- 

 thetical, and we may leave the subject with the general con- 

 clusion that with the typical fish advance in structure has 



