( 12.) 
ment of his views on evolution in 1802, the celebrated 
‘Philosophie Zoologique” was not published until 1809, 
fifteen years after the appearance of the ‘‘ Zoonomia,” and it 
is uncertain whether the author of the later work had ever 
seen the earlier treatise. Professor Osborn concludes upon 
the whole that he had not (/. ¢., pp. 152—155). However this 
may be, the technical use of the words “acquired characters ” 
is chiefly due to his memoir. The essential passages are 
the two following Laws of Lamarck :— 
“ Pyemiére Loi.mDans tout animal qui n’a point depassé le 
terme de ces developpements, l'emploi plus fréquent et soutenu 
dun organe quelconque, fortifie peu a4 peu cet organe, le de- 
veloppe, Paggrandit, et lui donne une puissance proportionnée a 
la durée de cet emploi; tandis que le défaut constant d’usage 
de tel organe, l’affaiblit insensiblement, le détériore, diminue 
progressivement ces facultés, et finit par le faire disparaitre.” 
“ Deuxieme Loi.—Tout ce que la nature a fait acguérir ou 
perdre aux individus par Vinfluence des circonstances ot leur 
race se trouve depuis longtemps exposée, et par conséquent par 
Vinfluence de l’emploi prédominant de tel organe, ou par celle 
dun défaut constant dusage de telle partie, elle le conserve 
par la génération aux nouveaux individus qui en proviennent, 
pourvu que les changements acquis soient communs aux deux 
sexes ou 2 ceux qui ont produit ces nouveaux individus.” * 
Opposite to the characters which Lamarck spoke of as 
“acquired” are the characters which may be called con- 
stitutional, congenital, genetic, inborn, innate or inherent. Other 
names have been specially proposed in order to render apparent 
the distinction between these two classes of characters. 
Weismann employed terms which set forth their different 
origin. The inherent he called blastogenic, expressing an origin 
that lay far back in germ-cell from which the individual arose. 
Acquired characters he called somatogenic, to express a later 
origin due to circumstances which had affected the body-cells. 
’ 
* “Philosophie Zoologique,” tome i. p. 235, Edition Savy, 1873: 
quoted by Professor E. R. Lankester in ‘‘ Nature,” vol. xli, 1890, p. 415. 
There had been a tendency in the discussion on this subject to protest 
against the restricted application of the word ‘‘acquired,”’ and it was 
assumed that the use was quite recent, and in fact due to Professor 
Weismann himself. Professor Lankester shows the error of this 
assumption. 
