PahHontology and the Biogenetic Law. — von Zittel. 149 
begin with those branches and twigs from our stems which 
are already more clearly differentiated and of which the ma- 
jority stretch down as far as the creation of our ow^n daj'^. 
Here again, then, we should be led to ground our classifica- 
tions on those organisms of which we were in a position to 
investigate not merely certain fossilisable elements, but the 
whole anatomj', physiology and embryology. 
The function of classification, however, is not only to ar- 
range organized beings according to their relationship, but 
also to facilitate our survey of life's infinite variety of form. 
It was to this intent that the older systematists constructed 
their various categories. They it is that have historic rights; 
and just as little as we geologists are inclined, without urgent 
need, to alter the historic conceptions and the divisions that 
have been handed down to us, just so little is it advisable to 
be incessantly remodelling the systems of botany and zoology. 
The doctrine of descent has, of course, violently shaken the 
solid framework of the older classification. The ideas — vari- 
ety, mutation, species, genus, family, order, etc. — have become 
indefinite and unstable ; the boundaries between the syste- 
matic groups are constantly being displaced, and bonds are 
burst that were once tightly bound. An important part is 
played to-day by subjective opinions, and when I think of the 
anxiety with which we elders — we who received our scientific 
education before the Darwinian era — proceeded to found a 
new species or genus and compare it with the light-hearted 
manner in which to-day species, genera, families and orders 
are set up and again put down, I am herein most forcibly im- 
pressed by the difference between then and now. The domi- 
nation of the Linnpean and Cuvierian principles threatened 
systematic biology with soulless paralysis : the unbridled 
subjectivity of recent times may easily lead to anarchj^ 
When, after investigating a certain number of forms, every 
author feels called upon to reform the classification and 
where possible to introduce a new terminology, then arises the 
danger that we shall lose our comprehensive survey of the 
richly varied organic world and that we shall use a language 
intelligible only to the most narrow specialists and repellant 
to every layman. 
