PREFACE. IX 



Tlic most startling of tlie new views, that, namely, 

 on the identity of Growth and Generation, has re- 

 cently received striking confirmation in the admirable 

 researches of Professor Huxley on the Aphides — re- 

 searches which render the facts I have observed in the 

 development of Polypes less paradoxical than they 

 originally appeared. 



Richmond, January 1858. 



