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support to the belief that evolution has operated within certain 
limits, and has been one of the causes which has led to the 
production of new forms. Even in the best-preserved groups, 
however, we meet constantly with isolated types, and we are 
incessantly met with the sudden appearance of new types. An 
excellent example of this is to be found in the sudden appear- 
ance of new species of Ammonites in the Liassic rocks, and 
their very definite range and complete limitation to known 
zones. The study of such groups would, therefore, lead us to 
reject any exclusive doctrine of evolution. 
8. Whilst certain types of life exhibit a striking variability, 
others exhibit an equally striking persistence and immobility. 
This w'ould go far to prove that changes in external conditions 
have little to do with the origin of variations ; since some forms 
appear to vary even under approximately constant conditions, 
whilst others remain unchanged even when submitted to the 
most varying surroundings. 
9. In some instances, it can even be shown that entire 
groups of species have existed without change through periods 
which we may justly estimate as exceedingly long. Thus, 
Principal Dawson affirms that of more than two hundred 
species of fossils, chiefly Mollusca, from the Post-Pliocene de- 
posits of Canada, no one form can be shown to have varied 
materially, during the long period w'hich separates the oldest 
boulder-clay from the present time, and in spite of notable 
climatal and geographical changes. 
10. Upon the whole, we may conclude that palaeontology, 
in its present stage of development, offers no strong support, 
or is directly opposed, to the special theory of the Origin of 
Species advocated by Mr. Darwin. On the other hand, many 
known palaeontological facts would lead us to infer that, in 
certain cases and within certain limits, new forms have been 
produced by the modification of pre-existent types. Palae- 
ontology, therefore, would appear to support, at any rate, a 
partial doctrine of evolution. 
11. It remains for future consideration, whether evolution — 
in so far as it has operated at all — has not been effected by 
means of inherent tendencies impressed upon living beings by 
the Creator. On this view, evolution is not a mere disorderly 
and fortuitous process, by which a given animal or plant is 
produced out of a different one by the operation of chance and 
accidental surroundings ; but it becomes an orderly process, by 
which certain forms of life have from the beginning been im- 
pressed with the inherent power of developing in certain fixed 
