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sional points by secondary changes. . . . An analysis of the stages 
during the life of one individual can in no way present a knowledge of its 
ancestry, and the method of comparing non-correspondent stages of two 
species is wrong in principle.” Equally sweeping is the statement of 
Hurst (30): “The ontogeny is not an epitome of the phylogeny, is not 
even a modified or ‘falsified’ epitome, is not a record, either perfect or im- 
perfect of past history, is not a recapitulation of evolution.” 
It would seem as though two statements could not be more flatly con- 
tradictory than these of Hurst and Montgomery, and that of Bather quoted 
above. Nevertheless I venture to make the seemingly paradoxical asser- 
tion that both parties to the controversy may be right, for the simple rea- 
son that they are talking about quite different things. This has been 
nowhere better expressed than by Grabau (25). He says: “It has been 
the general custom to test the validity of the recapitulation theory by the 
embryological method; i. e., the comparableness of the changes which the 
individual undergoes during its embryonic period te the adults of more 
primitive types. Usually the comparison has been with the adults of ex- 
isting types, since in most cases these alone were available for compari- 
son. It is no wonder, then, that such comparisons have led to innumer- 
able errors, if not absurdities, which have placed the recapitulation theory 
in an evil light and awakened in the minds of many serious investigators 
doubts as to the validity of the deductions based upon this doctrine. When, 
however, the entire life history of the individual is considered, instead of 
only the embryonic period, and when the successive stages of epembryonic 
development are compared with the adult characters of related types, in 
immediately preceding geologic periods, it will be found that the funda- 
mental principle of recapitulation is sound, and that the individuals do 
repeat in their own cpembryonic development the characters of their own 
immediate ancestors.” (Italics mine.) 
It is as a matter of fact true that the Hyatt school of paleontologists 
have based their phylogenies on epembryonic rather than embryonie stages 
—stages beginning with the nepionic or infantile—since in the nature of 
the case the true embryonic stages are scarcely ever accessible to the stu- 
dent of fossils. It is no less true that the severest critics of the theory 
of recapitulation have rested their case largely on the real or supposed 
lack of correspondence between the embryonic stages and the adult stages 
of assumed ancestors, or upon certain @ priori considerations having to 
