IN THE LAST HALF-CENTURY. 121 



preparation, which enable the anatomist 

 to exhanst the details of visible structure 

 and to reproduce them with geometrical 

 precision, have investigated every impor- 

 tant group of living animals and plants, no 

 less than the fossil relics of former faunae 

 and florae. An enormous addition has 

 thus been made to our knowledge, espe- 

 cially of the lower forms of life, and it 

 may be said that morphology, however 

 inexhaustible in detail, is complete in its 

 broad features. Classification, which is ! 

 merely a convenient summary expression 

 of morphological facts, has undergone a 

 corresponding improvement. The breaks 

 which formerly separated our groups from 

 one another, as animals from plants, ver- 

 tebrates from invertebrates, cryptogams 

 from phanerogams, have either been filled 

 up, or shown to have no theoretical sig- 

 nificance. The question of the position 

 of man, as an animal, has given rise to 

 much disputation, with the result of prov- 



