LAW OF ACCELERATION. AZ 
being due to the law of natural selection. We do not deny the existence of 
such examples; we are only anxious to hear of their existence, and to be able 
to examine the evidence. 
Weissmann‘ also seems to have been unacquainted with the same literature, 
and claims the discovery of the law of acceleration for Wiirtenberger. Weiss- 
mann’s interpretations of the phenomena were in part very similar to our own. 
He rejected Wiirtenberger’s theory of the origin of acceleration through the 
action of natural selection, and states that it is due to the innate law of growth, 
which rules every organism. In many places he explains this law of growth as 
a mechanical law, and the origin of variations as due to the innate response of 
the organism to external forces exciting it to suitable changes. This law of 
variation through mechanical causation is identical with that advocated by Cope, 
Ryder, and the author; but with regard to this there can probably be no contro- 
versy about priority. Dr. A. $8. Packard has shown that such views are essen- 
tially rehabilitations and improvements upon Lamarck’s theory of effort, and he 
has appropriately named us the Neo-Lamarckian school. 
This eminent author (Weissmann) has apparently abandoned this position in 
his later works. He claims that the protoplasmic basis of organisms is alone 
the vehicle of heredity, and substantially imperishable or continuous; that all 
variations taking place in the organisms, unless they affect this basis so as to 
modify the ovum, are not inherited; that the variations of males and females are, 
when inherited in the offspring, the originators of new characters through the 
new combinations which necessarily arise, and he also regards natural selection 
as the prime agent in the preservation and perpetuation of these variations.’ We 
have been unable to find any characters which were not inheritable in some series. 
The behavior of all characteristics which have been introduced into any series 
of species shows them to be subject to the law of acceleration, in whatever way 
they have originated, whether primarily as adaptive characters, according to our 
hypothesis, or by natural selection and through the combination of the sexual 
variations, as supposed by Weissmann. All of the degenerative changes took 
place in retrogressive series, in precisely the same way as is described above for 
progressive changes. Thus, the degradational characters and uncoiling became 
noticeable in the old of individuals and of species first, and then appeared, in 
obedience to the law of acceleration of development, at earlier stages in suc- 
ceeding or derivative forms, until finally they entirely replaced the normal 
progressive characteristics of the nealogic stages. A straight Baculites-like modi- 
fication could not have been produced by the unfavorable surroundings directly 
from any close-coiled form; it must have arisen from the intermediate arcuate 
and crioceran modifications. If this be true, heredity must have played its part 
even in the extreme modifications of abnormal geratologous series, however 
improbable this may seem. 
1 Studies in the Theory of Descent, Eng. ed., transl. by Meldola, I. pp. 274, 277. 
2 Standard Natural History, edited by Kingsley, Introduction; and also Cope’s “ Origin of the Fittest,” 
in which see index, Lamarck. 
8 Continuitiit der Keimplasmas; also Ueber der Vererbung; see also, as in favor of the views here ad- 
vanced, Kolliker’s criticism, Karyoplasma und Vererbung, Zeit. Wissensch. Zool., XLIV., 1886. 
Saeenener es 
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