2l8 DARWIN. 



ment, the author adds a second impulse, tending to 

 modify organic structures in accordance with their 

 environment, food, nature of the habitat, meteoric 

 agencies, and thus to produce the ' adaptations ' 

 of the natural theologian. 



This progressive advance with modification would 

 also leave a gap at the bottom of the scale ; to fill 

 this up, the author, like Lamarck, supposes that 

 there is a continuous spontaneous generation of 

 the lowest forms of life, of primordial nucleated 

 vesicles, the meeting-point between the organic 

 and inorganic ; this generation he believes to be an 

 electro-chemical operation. 



The author has been aptly termed a ' pro- 

 gressionist,' because of his belief in the inter- 

 nal perfecting or ' progressing ' principle. Owen, 

 and in a measure Louis Agassiz, should also be 

 classed as ' progressionists.' 



RICHARD OWEN (1810-1892), whose recent death 

 marked the last of the old school, was the leading 

 comparative anatomist of the world in the period 

 after Cuvier, with whom he studied. 



He was not, however, a scientific successor of 

 Cuvier in a strict sense, but followed also St. 

 Hilaire and Oken in Philosophical Anatomy 

 and in a guarded acceptance of the transmuta- 

 tion theory. From Oken and Goethe he de- 

 veloped his famous, but now wholly discarded, 

 theory of the skull, as derived from the modifica- 

 tions of vertebrae ; the idea of archetypal or perfect 



