The Phyletic Museum At Jena. 
BY ERNST HAECKEL. 
URING the last half century the idea of a natural 
ED development of creation has won importance and 
acceptance unthought of at any earlier date. Until 
near the middle of the nineteenth century, development as 
a doctrine was confined to investigation of the genesis and 
formation of separate things ; especially to the life-history 
of individual organic beings. Botanical and zoological 
text-books, and university lectures on development, till 
1850, merely considered the germination of plants, and 
embryology of animals, or at most entered into particulars 
of their metamorphoses. Not until 1859, when Darwin 
put forth his theory of natural selection, thereby supplying 
firm foundation to the doctrine of descent taught half a 
century earlier by Lamarck, did the origin of species from 
orders and classes of plants and animals, a special part of 
the development theory, find recognition. My ‘‘ General 
Morphology,”’ in 1866, first claimed this as an independent 
branch of biology. Under the name of Phylogeny or race 
history, it was ranked with Ontogeny or individual history, 
an older branch of the science of living things. And 
in my ‘‘Biogenetischen Grundgesetze,’’ I sought to 
express the causal relationship existing between these 
equally authoritative branches of the development theory. 
Ontogeny is but a shortened, and, with manifold changes, 
a condensed recapitulation of Phylogeny. 
The significance of the modern doctrine of develop- 
ment is evident from its important conclusion that the 
descent of man is from other vertebrate animals. For by 
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