308 
Nor would I create the impression that the embryologists and zoolo- 
gists have utterly deserted the paleontologists in their support of the re- 
capitulation theory. Several recent papers give considerable aid and com- 
fort to those of us who still believe in recapitulation. I shall introduce 
here the conclusions of three of these workers, more particularly because 
it will afford me an opportunity to correct what I hold to be another error 
of those who oppose the theory. 
One of the most interesting pieces of evidence that has recently been 
adduced in favor of the idea that ontogeny recapitulates phylogeny is to 
be found in a paper by Griggs on “Juvenile Kelps” (28). It is not my 
purpose, however, to discuss the very interesting evidence which he has 
recorded, but ratber to quote his remarks on the views of His and Morgan, 
and his general conclusions. His maintains that the reason why ontogeny 
seems to recapitulate phylogeny is because the stages in development are, 
as Griggs paraphrases it, ‘only the physiologically necessary steps for the 
formation of the adult body from its earliest stage, which in most cases 
is the egg.” With the ideas of Morgan as expressed in his valuable book 
on “Evolution and Adaptation” we are all familiar. He holds that or- 
ganisms repeat in their development, not adult stages, but only embryonic 
stages of their ancestors. To this idea he has given the name of “repe- 
tition.” 
On this point of the recapitulation of embryonic conditions Griggs 
makes the following pertinent statements: “In the toothless animals, the 
whale and the bird, the development of teeth in the jaws is entirely un- 
necessary * * * it may even be said to hinder the attainment of the 
adult condition. The same is true of the mammalian gill slits and of 
most structures which have in the past attracted attention in connection 
with the recapitulation theory. As the ancestral period when such struc- 
tures were fully developed in the adult becomes more and more remote, 
the tendency to inherit them becomes less and less, because of the cumu- 
lative impulses given to the heritage by the nearer ancestors. Conse- 
quently they are successively less and less developed. Any gradual loss 
of inheritance can, in the nature of the case, take place only from the 
mature condition backward toward the beginning of the life cycle; other- 
wise we should have adult structures with no ontogenetic history. There- 
fore we can understand why it is that in many cases only the embryonic 
stages of ancestral history persist in the ontogeny.’ In a foot note he 
comp 
says: he cutting off of end stages in the development of organs has 
