288 THE REIGN OF LAW. 



no bad jokes. Whatever natural things really 

 point to, they point to faithfully ; and the con- 

 clusions really indicated are never false. Abortive 

 organs mean something, and they mean it truly. 



Still, there is no proof that Inheritance is the 

 only cause from which such structures can arise. 

 In the inorganic world we know that not mere simi- 

 larity, but absolute identity of form, as in crystals, 

 is the result of laws which have nothing to do with 

 Inheritance, but of forces whose nature it is to 

 aggregate the particles of matter in identic shapes. 

 It is impossible to say how far a similar unity of 

 effect may have been impressed on the forces 

 through which vital Organisms are first started on 

 their way. There are some essential resemblances 

 between all Forms of Life which it is impossible 

 even in imagination to connect with community of 

 blood by descent. For example, the Bilateral ar- 

 rangement is common to all Organisms, down at 

 least to the Radiata, and in this great class we 

 have the same principle of Polarity developed in 

 a circle. Again, the general mechanism of the 

 digestive organs by which food is in part assimi- 

 lated and part rejected, is also common through a 



