SUD resS FOR >TUDENTS. 
COMPARATIVE STUDY OF PALASONTOGENY AND 
PEvwicOGE NY. 
CONTENTS. 
Introduction. 
Law of acceleration of development. 
Nomenclature of stages of growth. 
Palzontogeny. 
Groups available. 
Brachiopoda. 
Crustacea. 
Mollusca. 
Pelecypoda. 
Cephalopoda. 
Method of working. 
INTRODUCTION. 
PALAZONTOLOGY ought to be synonymous with phylogeny, and 
biology with ontogenetic study; but when most paleontologists 
are content to describe species from a few characteristics of 
adults, and to guess at their relationships and history, and when 
many zodlogists are satisfied with basing species on color or 
some other minor mark, while the life history of even most liv- 
ing forms is wholly unknown, the need of higher ideals is 
evident. 
All modern classification is intended to be genetic and is 
based on comparison of a series of adults from successive ages 
of the earth, of which the present time is but anepisode. Inter- 
esting and valuable investigations in phylogeny have been 
made in this way, but such genealogies cannot, as a matter of 
course, be more than approximate, for the geologic record itself 
is incomplete, and the life record still more fragmentary. We 
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