TEEVIRANUS, THE FIRST NATUEE-PHILOSOPHEE. 93 



Bremen (born 1776, died 1837), was zealously engaged at 

 the same work. As Wilhelm Focke has recently shown, 

 Treviranus, even in the earliest of his greater works, " The 

 Biology or Philosophy of Animate Nature," which appeared 

 at the beginning of the present century, had already 

 developed monistic views of the unity of nature, and of the 

 genealogical connection of the species of organisms, which 

 entirely correspond with our present view of the matter. In 

 the first three volumes of the Biology, which appeared succes- 

 sively in 1802, 1803, and 1805 (therefore several years before 

 Oken's and Lamarck's principal works), we find numerous 

 passages which are of interest in this respect. I shall here 

 quote only a few of the most important. 



In speaking of the principal question of our theory, the 

 question of the origin of organic species, Treviranus makes 

 the following remarks : — " Every form of life can be 

 produced by physical forces in one of two ways : either by 

 coming into being out of formless matter, or by modification 

 of an already existing form by a continued process of 

 shaping. In the latter case the cause of this modification 

 may lie either in the influence of a dissimilar male genera- 

 tive matter upon the female germ, or in the influence of 

 other powers which operate only after procreation. In every 

 living being there exists the capability of an endless variety 

 of form-assumption ; each possesses the power to adapt its 

 organization to the changes of the outer world, and it is this 

 power put into action by the change of the universe that 

 has raised the simple zoophytes of the primitive world to 

 continually higher stages of organization, and has introduced 

 a countless variety of species into animate nature." 



By zoophytes, Treviranus here means organisms of the 



