In September of 1830 Lyell spent six weeks working in the private museum of 
Gérard Paul Deshayes (1797-1875), one of the best contemporary conchologists. In 
important ways, the scientific results of these journeys determined the 
character of the Principles of geology : his geological observations convinced 
Lyell that it was possible to produce a detailed formulation of what has been 
characterized as his uniformitarian and ‘steady-state’ model of explanation of 
geological phenomena ; his renewed acquaintance with many leading French 
naturalists, and the fertile discussions he had with them, reinforced his 
awareness of the degree to which geological questions were integrally related to 
the most fundamental problems of natural history. This paper will emphasize the 
extent to which Lyell's intimacy with the latest developments in the natural 
sciences in France permeated those chapters of the second volume of the 
Principles concerned with the question of species.
 

I

The theme which constituted the implicit polemical centre of Lyell’s second 
volume was Lamarck's theory of the transmutation of species, as formulated both 
in the Philosophie zoologique and in the Histoire naturelle des animaux sans 
vertèbres (5).
 

It is generally believed that in the early nineteenth century Lamarck’s name was 
primarily, and negatively, linked with his transformist hypothesis. It is true 
that Lamarck's transformist ideas aroused considerable opposition, and 
contributed to his considerable - but not at all total - isolation in the French 
scientific world. But his botanical work and his several memoirs on conchology 
which were published in the Annales du Muséum and other scientific journals, 
together with his Histoire naturelle des animaux sans vertèbres, published 
between 1815 and 1822, won general acceptance among European naturalists. 
Lamarck's influence, which contributed to the abandonment of the Linnaean system 
of classification in the group of animals Lamarck called ‘invertebrates’, was 
also felt in Britain. The works of Samuel Brooke (1815), of the Sowerby family 
(1820-34), and of W. Turner (1822), successfully introduced Lamarck's taxonomic 
proposals to English naturalists.
 

The Scottish naturalist John Fleming (1785-1857), whom Lyell greatly admired, 
published his Philosophy of zoology, or a general view of the structure, 
function and classification of animals in 1822. Fleming's avowed intention was 
to give further impulse to a vitalistic theory of life, in support of the 
Inquiry into the opinions, ancient and modern, concerning life and organization 
(1822) by John Barclay (1758-1826). Fleming opposed materialistic tendencies 
which had appeared in the biological and physiological sciences, believing in a 
‘vital principle’ inherent in the embryo or germ, having the power of 
‘developing in succession the destined plan existence’. By means of this power, 
the germ was able to attract particles 

(5) J. B. P. A. Monet de Lamarck, Philosophie zoologique, ou exposition des 
considérations relatives à l'histoire des animaux, Paris 1809 ; Histoire des 
animaux sans vertèbres, Paris, 1815-22. See also : M. Landrieu, Lamarck, le 
fondateur du transformisme, sa vie, son oeuvre, Paris. 1909 ; H. Daudin, Cuvier 
et Lamarck : les classes zoologiques et l'idée de série animale (1790-1830), 2 
vols., Paris, 1926. For reviews of recent themes in Lamarckian studies, see R. 
W. Burkhardt, ‘Lamarck and the politic of science’, Journal of the history of 
biology, 1970, 3, 270-98, and ‘The inspiration of Lamarck's belief in 
evolution’, ibid., 1972, 5, 13-38 ; E. Mays, ‘Lamarck revisited’, ibid. 1972, 5, 
55-94 ; R. W. Burkhardt The spirit of system : Lamarck and evolutionary biology, 
Cambridge, Mass., 1977 ; L. J. Jordanova, The natural philosophy of Lamarck in 
its historical context, University of Cambridge PhD thesis, 1976.