396 LAMARCK, HIS LIFE AND WORK 



primary factors of organic evolution, such as the 

 change of environment, whether the factors be cos- 

 mical (gravity), physical changes in temperature, 

 effects of increased or diminished light and shade, 

 under- or over-nutrition, and the changes resulting 

 from the presence or absence of enemies, or from iso- 

 lation. The action of these factors, whether direct 

 or indirect, is obvious, when we try to explain the 

 origin or causes of the more marked metamorphoses 

 of animals. Then come in the other Lamarckian 

 factors of use and disuse, new needs resulting in 

 new modes of life, habits, or functions, which bring 

 about the origination, development, and perfection 

 of new organs, as in new species and genera, etc., or 

 which in metamorphic forms may result in a greater 

 increase in the number of, and an exaggeration of 

 the features characterizing the stages of larval life. 



"VI. The Adequacy of Neolamarckism. 



" It is not to be denied that in many instances all 

 through the ceaseless operation of these fundamen- 

 tal factors there is going on a process of sifting or of 

 selection of forms best adapted to their surround- 

 ings, and best fitted to survive, but this factor, 

 though important, is quite subordinate to the initial 

 causes of variation, and of metamorphic changes. 



" Neolamarckism,* as we understand this doctrine, 



* In 1S85, in the Introduction to the Standard Natural History, 

 we proposed the term Neolamarckianism, or Lamarckism in its 

 modern form, to designate the series of factors of organic evolution, 

 and we take the liberty to quote the passage in which the word first 

 occurs. We may add that the briefer form, Neolamarckism, is the 

 more preferable. 



" In the United States a number of naturalists have advocated 

 what may be called Neo-Lamarckian views of evolution, especially the 

 conception that in some cases rapid evolution may occur. The pres- 

 ent writer, contrary to pure Darwinians, believes that many species, 

 but more especially types of genera and families, have been produced 

 by changes in the environment acting often with more or less rapidity 



