154 ANIMAL INDIVIDUALITY [OH. vi 



altered mould, and thereby often taking on new and 

 unfamiliar shapes. 



The ancestral plan may persist in spite of present 

 uselessness, like the elaborate arrangement of the 

 lines of hair on the body and limbs of man; or it 

 may take on some new use, like our Eustachian tube, 

 in fish-like ancestors a gill-slit. It is by this in- 

 corporation of the old in the new that we can trace 

 such adventurous histories as that of the cell- 

 individual. 



But this persistence is not absolute : with necessity 

 and long lapse of time life seems able to cast away 

 every vestige of the old forms, as when gills are 

 replaced by lungs in air-breathing vertebrates, or 

 when a metazoan structure, once cellular, builds 

 itself without cells. 



All roads lead to Rome: and even animal indi- 

 viduality throws a ray on human problems. The ideals 

 of active harmony and mutual aid as the best means to 

 power and progress ; the hope that springs from life's 

 power of transforming the old or of casting it from 

 her in favour of new ; and the spur to effort in the 

 knowledge that she does nothing lightly or without 

 long struggle : these cannot but help to support and 

 direct those men upon whom devolves the task of 

 moulding and inspiring that unwieldiest individual- 

 formless and blind to-day, but huge with possibility 

 the State. 



