38 THE HISTORY OF CREATION, 
Four years ago I set up a number of hypothetical genea- 
logies for the larger grcups of organisms in the systematic 
introduction to my General History of Development (Gen. 
Morph. vol. i), and thereby,in fact, made the first attempt 
actually to construct the pedigrees of organisms in the 
manner required by the theory of development. I was 
quite conscious of the extreme difficulty of the task, and as 
I undertook it in spite of all discouraging obstacles, I claim 
no more than the merit of having made the first attempt and 
given a stimulus for other and better attempts. Probably 
most zoologists and botanists were but little satisfied with 
this beginning, and least so in reference to the special domain 
in which each one is specially at work. However, it is cer- 
tainly in this case much easier to blame than to produce 
something better, and what best proves the immense diffi- 
culty of this infinitely complicated task is the fact that no 
naturalist has as yet supplied the place of my pedigrees by 
better ones. But, like all other scientific hypotheses which 
serve to explain facts, my genealogical hypotheses may 
claim to be taken into consideration until they are re- 
placed by better ones. 
I hope that this replacement will very soon take place ; 
and I wish for nothing more than that my first attempt 
may induce very many naturalists to establish more accurate 
pedigrees for the individual groups, at least in the special 
domain of the animal and vegetable kingdom which 
happens to be well known to one or other of them. By 
numerous attempts of tuis kind our genealogical know- 
ledge, in the course of time, will slowly advance and 
approach more and more towards perfection, although it can 
with certainty be foreseen that we shall never arrive ata 
