TREVIRANUS, THE FIRST NATURE-PHILOSOPHER. 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 
