142 



THE AMERICAN NATURALIST [Vol. LVI 



just as embryologists and geneticists are observing the 

 modes of development, from the fertilized ovum to the 

 mature individual, without in the least understanding 

 either the cause or the nature of the process of develop- 

 ment which goes on under their eyes every day. 



In conclusion, it is the great biological achievement 

 of the last half century that palaeontologists have dis- 

 covered Jioiv new characters and new species originate. 

 It may be the achievement of the experimental biologists 

 during the next half century to explain ivhy new char- 

 acters and new species originate. 



1890.47 The Palaeontological Evidence for the Transmission of Acquired 



1891 .5.3 Are Acquired Variations Inherited? (Opening n Discussion upon 

 the Lanij.rekian- Principle in Evolution. American Society of 

 Naturalists, Boston, Dec. .31, 1890.) Amer. Naturalist, Vol- 



1894.92 Certain Principles of Progressively Adaptive Variation Ob- 

 served in Fossil Series. Nature. Vol. 50, No. 129() p. 4.35. 



1895.97 The Hereditary Mechanism and the Search for the Unknown 

 Factors of Evolution. Biol. Lectures. IVrnrine Biol Lnh of 

 W..(„ls Holl. 1S!)4. Ginn & Co.. Boston, 1S95. 



1896.108 |Al,srr.] [A Mode of Evolution requiring neither Natural Se- 

 lection nor the Inheritance of Acquired Characters.] Tnui.*. 

 A 1 Acad Sci,\ol \\,Mir 9 ui.l Vpr 13 Is'H, pp 141, 

 142. 148. 



1898.134 The Biological Problems of To-day: Palaeontological Problems 



eiety of Naturaiists.] iiarnce, Vol. VIF. No. 162, pp. 



145-147. 



1902.212 Homoplasy as a Law of Latent or Potential Homology. Amcr 

 1907..30.3 Evolution as It Appears to the Palaeontologist- Srir,,.; \ w 

 1908.314 Coincident Evolution Through Rectigradaticns. , \ s 



1909.331 To the Philosophic Zoologist. Science. NS. Vol KXIX \o 



