REVIEWS. 235 
recorded is identical with those of Professor Cope's more elaborate essay. 
ave no desire for controversy and regard scientific claims as gener- 
ally speaking not worth contending for, but feel that silence, in the present 
instance, would place in a false light the object of these investigations, 
and vitiate the original value of the results of much labor not yet pub- 
lished. The quotation below will serve to justify these remarks, and at 
the same time bring us back to the more agreeable and legitimate subject 
of this review. 
“ This law” (of acceleration) ** applied to such groups as have been 
t 
growth, greater differences which in turn become embryonic, and so on; 
but when the same law acts upon some series whose individuals alter the 
place. The old age characteristics in due course of time or structure, 
characteristics first found in the old age of the shell, which are Pria 
at earlier periods hy species standing higher in the series, just as 
aes characteristics are inherited by them in the young. Thus the oe 
radation and ultimate extinction of groups of animals may be accounted 
for by the law of acceleration quite as accurately as their rise and pro- 
gress in organization. 
These de adito tendencies bring about in the old age. of the indi- 
liar unrolled shells of the Cretaceous Ammonites, which are, form for 
form, the same as those of the earlier Nautiloids in the older formations. 
e 
Shown to be degraded species; in their simpler septa when compared 
with the normal formed ammonites, having in the adult only the six lobes 
of the young, and in their ornamentation, and simple, rounded, keeless 
and channelless whorls. 
e retardation of development which is invoked to account for 
vet and the group to which it may i. The struggle for exist- 
M the action of this law, but that it has no controlling influence is 
of *“On the Paralellism," p. 232. 
f First noticed by Doa Pi Franeaise. Terr. Cretaces p. 381. 
