278 THE HISTORY OF CREATION. 
remote period in which life on our planet began with the 
spontaneous generation of Monera, organisms of all groups, 
both collectively as well as individually, have continually 
become more perfectly and highly developed. The steadily 
increasing variety of living forms has always been accom- 
panied by progress in organization. The lower the strata 
of the earth in which the remains of extinct animals and 
plants lie buried, that is, the older the strata are, the more 
simple and imperfect are the forms which they contain. This 
applies to organisms collectively, as well as to every single 
large or small group of them, setting aside, of course, those 
exceptions which are due to the process of degeneration, 
which we shall discuss hereafter. 
As a confirmation of this law I shall mention only the 
most important of all animal groups, the tribe of vertebrate 
animals. The oldest fossil remains of vertebrate animals 
known to us belong to the lowest class, that of Fishes. Upon 
these there followed later more perfect Amphibious animals, 
then Reptiles, and lastly, at a much later period, the most 
‘highly organized classes of vertebrate animals, Birds and 
Mammals. Of the latter only the lowest and most imperfect 
forms, without placenta, appeared at first, such as are the 
pouched animals (Marsupials), and afterwards, at a much 
later period, the more perfect mammals, with placenta. Of 
these, also, at first only the lower kinds appeared, the higher 
forms later ; and not until the late tertiary period did man 
gradually develop out of these last. 
If we follow the historical development of the vegetable 
kingdom we shall find the same law operative there. Of 
plants there existed at first only the lowest and most im- 
perfect classes, the Algz or tangles. Later there followed 
