THE ANCESTRY OF VERTEBRATES 
AS A MEANS OF UNDERSTANDING THE PRINCIPAL 
FEATURES OF THEIR STRUCTURE AND DEVELOPMENT 
e facts are related to the ideas of the 
science as statistics to history — meaningless 
without interpretation, 
W, A. LOCY, Biology and its makers. 
Vermögen naiver Beobachtung verliert und 
damit die 
W. HIS, 1887, p. 380. 
Lì. Stomodaeum and medullary tube. 
Phylogeny, the study of the evolution of life on earth, 
has lost the universal veneration paid to it by a former 
generation of zoologists. As a guiding thread in systematic 
studies on restricted groups it still may do service; but the 
general discouragement evoked by so numerous vain attempts 
to trace the relations of the main branches of the genealo- 
gical tree of the animal kingdom has diverted attention from 
the great work of the reconstruction of this tree to other 
problems and other paths of science, neglected until now. 
How much interest did a theory on the origin of Verte- 
brates awake some thirty or forty years ago. How little, 
l fear, will it do in our materialistic days! New and vain 
speculations on things we can never know, new hypotheses 
based on a hypothesis: the theory of evolution. What is 
their value? Give us facts! 
It is to encounter these objections that 1 gave this article 
a sub-title which, I hope, will need no further elucidation. 
It is equally as a plea pro domo —l nearly would have said: 
as an excuse for my boldness to treat of such a subject — 
that 1 placed the first quotation under the title, though, as 
a complement, 1 added the second under it. And further, 
may the theory to be exposed here speak for itself and 
